diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/MySqlCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/MySqlCodeFirstTest.cs
index 98cec1d3..8d279e69 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/MySqlCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/MySqlCodeFirstTest.cs
@@ -282,57 +282,7 @@ namespace FreeSql.Tests.MySqlConnector
         {
 
             var sql = g.mysql.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-            if (string.IsNullOrEmpty(sql) == false)
-            {
-                Assert.Equal(@"CREATE TABLE IF NOT EXISTS `cccddd`.`tb_alltype` ( 
-  `Id` INT(11) NOT NULL AUTO_INCREMENT, 
-  `testFieldBool` BIT(1) NOT NULL, 
-  `testFieldSByte` TINYINT(3) NOT NULL, 
-  `testFieldShort` SMALLINT(6) NOT NULL, 
-  `testFieldInt` INT(11) NOT NULL, 
-  `testFieldLong` BIGINT(20) NOT NULL, 
-  `testFieldByte` TINYINT(3) UNSIGNED NOT NULL, 
-  `testFieldUShort` SMALLINT(5) UNSIGNED NOT NULL, 
-  `testFieldUInt` INT(10) UNSIGNED NOT NULL, 
-  `testFieldULong` BIGINT(20) UNSIGNED NOT NULL, 
-  `testFieldDouble` DOUBLE NOT NULL, 
-  `testFieldFloat` FLOAT NOT NULL, 
-  `testFieldDecimal` DECIMAL(10,2) NOT NULL, 
-  `testFieldTimeSpan` TIME NOT NULL, 
-  `testFieldDateTime` DATETIME(3) NOT NULL, 
-  `testFieldBytes` VARBINARY(255), 
-  `testFieldString` VARCHAR(255), 
-  `testFieldGuid` VARCHAR(36), 
-  `testFieldBoolNullable` BIT(1), 
-  `testFieldSByteNullable` TINYINT(3), 
-  `testFieldShortNullable` SMALLINT(6), 
-  `testFieldIntNullable` INT(11), 
-  `testFielLongNullable` BIGINT(20), 
-  `testFieldByteNullable` TINYINT(3) UNSIGNED, 
-  `testFieldUShortNullable` SMALLINT(5) UNSIGNED, 
-  `testFieldUIntNullable` INT(10) UNSIGNED, 
-  `testFieldULongNullable` BIGINT(20) UNSIGNED, 
-  `testFieldDoubleNullable` DOUBLE, 
-  `testFieldFloatNullable` FLOAT, 
-  `testFieldDecimalNullable` DECIMAL(10,2), 
-  `testFieldTimeSpanNullable` TIME, 
-  `testFieldDateTimeNullable` DATETIME(3), 
-  `testFieldGuidNullable` VARCHAR(36), 
-  `testFieldPoint` POINT, 
-  `testFieldLineString` LINESTRING, 
-  `testFieldPolygon` POLYGON, 
-  `testFieldMultiPoint` MULTIPOINT, 
-  `testFieldMultiLineString` MULTILINESTRING, 
-  `testFieldMultiPolygon` MULTIPOLYGON, 
-  `testFieldEnum1` ENUM('E1','E2','E3') NOT NULL, 
-  `testFieldEnum1Nullable` ENUM('E1','E2','E3'), 
-  `testFieldEnum2` SET('F1','F2','F3') NOT NULL, 
-  `testFieldEnum2Nullable` SET('F1','F2','F3'), 
-  PRIMARY KEY (`Id`)
-) Engine=InnoDB;
-", sql);
-            }
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             sql = g.mysql.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -398,6 +348,7 @@ namespace FreeSql.Tests.MySqlConnector
                 testFieldShort = short.MaxValue,
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 testFieldTimeSpan = TimeSpan.FromSeconds(999),
                 testFieldTimeSpanNullable = TimeSpan.FromSeconds(60),
                 testFieldUInt = uint.MaxValue,
@@ -411,10 +362,12 @@ namespace FreeSql.Tests.MySqlConnector
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -561,6 +514,10 @@ namespace FreeSql.Tests.MySqlConnector
             public string TestFieldString { get; set; }
 
 
+            [JsonProperty, Column(Name = "testFieldChar", DbType = "char(1)", IsNullable = true)]
+            public char testFieldChar { get; set; }
+
+
             [JsonProperty, Column(Name = "testFieldTimeSpan", DbType = "time")]
             public TimeSpan TestFieldTimeSpan { get; set; }
 
@@ -665,6 +622,7 @@ namespace FreeSql.Tests.MySqlConnector
 
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
 
             public bool? testFieldBoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Dameng/DamengCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Dameng/DamengCodeFirstTest.cs
index be8559fe..fed58cd8 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Dameng/DamengCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Dameng/DamengCodeFirstTest.cs
@@ -179,57 +179,7 @@ namespace FreeSql.Tests.Odbc.Dameng
         {
 
             var sql = g.dameng.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-            if (string.IsNullOrEmpty(sql) == false)
-            {
-                Assert.Equal(@"CREATE TABLE IF NOT EXISTS `cccddd`.`tb_alltype` ( 
-  `Id` INT(11) NOT NULL AUTO_INCREMENT, 
-  `Bool` BIT(1) NOT NULL, 
-  `SByte` TINYINT(3) NOT NULL, 
-  `Short` SMALLINT(6) NOT NULL, 
-  `Int` INT(11) NOT NULL, 
-  `Long` BIGINT(20) NOT NULL, 
-  `Byte` TINYINT(3) UNSIGNED NOT NULL, 
-  `UShort` SMALLINT(5) UNSIGNED NOT NULL, 
-  `UInt` INT(10) UNSIGNED NOT NULL, 
-  `ULong` BIGINT(20) UNSIGNED NOT NULL, 
-  `Double` DOUBLE NOT NULL, 
-  `Float` FLOAT NOT NULL, 
-  `Decimal` DECIMAL(10,2) NOT NULL, 
-  `TimeSpan` TIME NOT NULL, 
-  `DateTime` DATETIME NOT NULL, 
-  `Bytes` VARBINARY(255), 
-  `String` VARCHAR(255), 
-  `Guid` VARCHAR(36), 
-  `BoolNullable` BIT(1), 
-  `SByteNullable` TINYINT(3), 
-  `ShortNullable` SMALLINT(6), 
-  `IntNullable` INT(11), 
-  `testFielLongNullable` BIGINT(20), 
-  `ByteNullable` TINYINT(3) UNSIGNED, 
-  `UShortNullable` SMALLINT(5) UNSIGNED, 
-  `UIntNullable` INT(10) UNSIGNED, 
-  `ULongNullable` BIGINT(20) UNSIGNED, 
-  `DoubleNullable` DOUBLE, 
-  `FloatNullable` FLOAT, 
-  `DecimalNullable` DECIMAL(10,2), 
-  `TimeSpanNullable` TIME, 
-  `DateTimeNullable` DATETIME, 
-  `GuidNullable` VARCHAR(36), 
-  `Point` POINT, 
-  `LineString` LINESTRING, 
-  `Polygon` POLYGON, 
-  `MultiPoint` MULTIPOINT, 
-  `MultiLineString` MULTILINESTRING, 
-  `MultiPolygon` MULTIPOLYGON, 
-  `Enum1` ENUM('E1','E2','E3') NOT NULL, 
-  `Enum1Nullable` ENUM('E1','E2','E3'), 
-  `Enum2` SET('F1','F2','F3') NOT NULL, 
-  `Enum2Nullable` SET('F1','F2','F3'), 
-  PRIMARY KEY (`Id`)
-) Engine=InnoDB;
-", sql);
-            }
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             //sql = g.dameng.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -272,6 +222,7 @@ namespace FreeSql.Tests.Odbc.Dameng
                 Short = short.MaxValue,
                 ShortNullable = short.MinValue,
                 String = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                Char = 'X',
                 TimeSpan = TimeSpan.FromSeconds(999),
                 TimeSpanNullable = TimeSpan.FromSeconds(60),
                 UInt = uint.MaxValue,
@@ -289,10 +240,12 @@ namespace FreeSql.Tests.Odbc.Dameng
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -323,6 +276,7 @@ namespace FreeSql.Tests.Odbc.Dameng
             public DateTime DateTimeOffSet { get; set; }
             public byte[] Bytes { get; set; }
             public string String { get; set; }
+            public char Char { get; set; }
             public Guid Guid { get; set; }
 
             public bool? BoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Default/OdbcCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Default/OdbcCodeFirstTest.cs
index f58d1305..b47bb3dc 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Default/OdbcCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Default/OdbcCodeFirstTest.cs
@@ -99,6 +99,7 @@ namespace FreeSql.Tests.Odbc.Default
                 testFieldShort = short.MaxValue,
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "鎴戞槸涓浗浜簊tring'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 testFieldUInt = uint.MaxValue,
                 testFieldUIntNullable = uint.MinValue,
                 testFieldULong = ulong.MaxValue,
@@ -117,10 +118,12 @@ namespace FreeSql.Tests.Odbc.Default
             var item3 = insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -148,6 +151,7 @@ namespace FreeSql.Tests.Odbc.Default
             public DateTime testFieldDateTime { get; set; }
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
 
             public bool? testFieldBoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/KingbaseES/KingbaseESCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/KingbaseES/KingbaseESCodeFirstTest.cs
index 271a76bf..2b6f2a61 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/KingbaseES/KingbaseESCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/KingbaseES/KingbaseESCodeFirstTest.cs
@@ -177,8 +177,8 @@ namespace FreeSql.Tests.Odbc.KingbaseES
         [Fact]
         public void GetComparisonDDLStatements()
         {
-
             var sql = g.kingbaseES.CodeFirst.GetComparisonDDLStatements<TableAllType>();
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             //sql = g.kingbaseES.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -221,6 +221,7 @@ namespace FreeSql.Tests.Odbc.KingbaseES
                 Short = short.MaxValue,
                 ShortNullable = short.MinValue,
                 String = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                Char = 'X',
                 TimeSpan = TimeSpan.FromSeconds(999),
                 TimeSpanNullable = TimeSpan.FromSeconds(60),
                 UInt = uint.MaxValue,
@@ -255,19 +256,22 @@ namespace FreeSql.Tests.Odbc.KingbaseES
                 a.DateTimeOffSet,
                 a.Bytes,
                 a.String,
+                a.Char,
                 a.Guid
             });
             var newitem22 = select.Where(a => a.Id == item2.Id).First(a => new
             {
-                a.Id, a.id2, a.SByte, a.Short, a.Int, a.Long, a.Byte, a.UShort, a.UInt, a.ULong, a.Double, a.Float, a.Decimal, a.TimeSpan, a.DateTime, a.DateTimeOffSet, a.Bytes, a.String, a.Guid
+                a.Id, a.id2, a.SByte, a.Short, a.Int, a.Long, a.Byte, a.UShort, a.UInt, a.ULong, a.Double, a.Float, a.Decimal, a.TimeSpan, a.DateTime, a.DateTimeOffSet, a.Bytes, a.String, a.Char, a.Guid
             });
 
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -298,6 +302,7 @@ namespace FreeSql.Tests.Odbc.KingbaseES
             public DateTime DateTimeOffSet { get; set; }
             public byte[] Bytes { get; set; }
             public string String { get; set; }
+            public char Char { get; set; }
             public Guid Guid { get; set; }
 
             public bool? BoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/MySql/MySqlCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/MySql/MySqlCodeFirstTest.cs
index 43176a37..3be75126 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/MySql/MySqlCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/MySql/MySqlCodeFirstTest.cs
@@ -153,57 +153,7 @@ namespace FreeSql.Tests.Odbc.MySql
         {
 
             var sql = g.mysql.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-            if (string.IsNullOrEmpty(sql) == false)
-            {
-                Assert.Equal(@"CREATE TABLE IF NOT EXISTS `cccddd`.`tb_alltype` ( 
-  `Id` INT(11) NOT NULL AUTO_INCREMENT, 
-  `testFieldBool` BIT(1) NOT NULL, 
-  `testFieldSByte` TINYINT(3) NOT NULL, 
-  `testFieldShort` SMALLINT(6) NOT NULL, 
-  `testFieldInt` INT(11) NOT NULL, 
-  `testFieldLong` BIGINT(20) NOT NULL, 
-  `testFieldByte` TINYINT(3) UNSIGNED NOT NULL, 
-  `testFieldUShort` SMALLINT(5) UNSIGNED NOT NULL, 
-  `testFieldUInt` INT(10) UNSIGNED NOT NULL, 
-  `testFieldULong` BIGINT(20) UNSIGNED NOT NULL, 
-  `testFieldDouble` DOUBLE NOT NULL, 
-  `testFieldFloat` FLOAT NOT NULL, 
-  `testFieldDecimal` DECIMAL(10,2) NOT NULL, 
-  `testFieldTimeSpan` TIME NOT NULL, 
-  `testFieldDateTime` DATETIME(3) NOT NULL, 
-  `testFieldBytes` VARBINARY(255), 
-  `testFieldString` VARCHAR(255), 
-  `testFieldGuid` VARCHAR(36), 
-  `testFieldBoolNullable` BIT(1), 
-  `testFieldSByteNullable` TINYINT(3), 
-  `testFieldShortNullable` SMALLINT(6), 
-  `testFieldIntNullable` INT(11), 
-  `testFielLongNullable` BIGINT(20), 
-  `testFieldByteNullable` TINYINT(3) UNSIGNED, 
-  `testFieldUShortNullable` SMALLINT(5) UNSIGNED, 
-  `testFieldUIntNullable` INT(10) UNSIGNED, 
-  `testFieldULongNullable` BIGINT(20) UNSIGNED, 
-  `testFieldDoubleNullable` DOUBLE, 
-  `testFieldFloatNullable` FLOAT, 
-  `testFieldDecimalNullable` DECIMAL(10,2), 
-  `testFieldTimeSpanNullable` TIME, 
-  `testFieldDateTimeNullable` DATETIME(3), 
-  `testFieldGuidNullable` VARCHAR(36), 
-  `testFieldPoint` POINT, 
-  `testFieldLineString` LINESTRING, 
-  `testFieldPolygon` POLYGON, 
-  `testFieldMultiPoint` MULTIPOINT, 
-  `testFieldMultiLineString` MULTILINESTRING, 
-  `testFieldMultiPolygon` MULTIPOLYGON, 
-  `testFieldEnum1` ENUM('E1','E2','E3') NOT NULL, 
-  `testFieldEnum1Nullable` ENUM('E1','E2','E3'), 
-  `testFieldEnum2` SET('F1','F2','F3') NOT NULL, 
-  `testFieldEnum2Nullable` SET('F1','F2','F3'), 
-  PRIMARY KEY (`Id`)
-) Engine=InnoDB;
-", sql);
-            }
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             sql = g.mysql.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -246,6 +196,7 @@ namespace FreeSql.Tests.Odbc.MySql
                 testFieldShort = short.MaxValue,
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 testFieldTimeSpan = TimeSpan.FromSeconds(999),
                 testFieldTimeSpanNullable = TimeSpan.FromSeconds(60),
                 testFieldUInt = uint.MaxValue,
@@ -265,10 +216,12 @@ namespace FreeSql.Tests.Odbc.MySql
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -391,6 +344,10 @@ namespace FreeSql.Tests.Odbc.MySql
             public string TestFieldString { get; set; }
 
 
+            [JsonProperty, Column(Name = "testFieldChar", DbType = "char(1)", IsNullable = true)]
+            public char testFieldChar { get; set; }
+
+
             [JsonProperty, Column(Name = "testFieldTimeSpan", DbType = "time")]
             public TimeSpan TestFieldTimeSpan { get; set; }
 
@@ -492,6 +449,7 @@ namespace FreeSql.Tests.Odbc.MySql
             public DateTime testFieldDateTime { get; set; }
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
 
             public bool? testFieldBoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Oracle/OracleCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Oracle/OracleCodeFirstTest.cs
index 95cd2720..5c0ead2e 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Oracle/OracleCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Oracle/OracleCodeFirstTest.cs
@@ -176,59 +176,8 @@ namespace FreeSql.Tests.Odbc.Oracle
         [Fact]
         public void GetComparisonDDLStatements()
         {
-
             var sql = g.oracle.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-            if (string.IsNullOrEmpty(sql) == false)
-            {
-                Assert.Equal(@"CREATE TABLE IF NOT EXISTS `cccddd`.`tb_alltype` ( 
-  `Id` INT(11) NOT NULL AUTO_INCREMENT, 
-  `Bool` BIT(1) NOT NULL, 
-  `SByte` TINYINT(3) NOT NULL, 
-  `Short` SMALLINT(6) NOT NULL, 
-  `Int` INT(11) NOT NULL, 
-  `Long` BIGINT(20) NOT NULL, 
-  `Byte` TINYINT(3) UNSIGNED NOT NULL, 
-  `UShort` SMALLINT(5) UNSIGNED NOT NULL, 
-  `UInt` INT(10) UNSIGNED NOT NULL, 
-  `ULong` BIGINT(20) UNSIGNED NOT NULL, 
-  `Double` DOUBLE NOT NULL, 
-  `Float` FLOAT NOT NULL, 
-  `Decimal` DECIMAL(10,2) NOT NULL, 
-  `TimeSpan` TIME NOT NULL, 
-  `DateTime` DATETIME NOT NULL, 
-  `Bytes` VARBINARY(255), 
-  `String` VARCHAR(255), 
-  `Guid` VARCHAR(36), 
-  `BoolNullable` BIT(1), 
-  `SByteNullable` TINYINT(3), 
-  `ShortNullable` SMALLINT(6), 
-  `IntNullable` INT(11), 
-  `testFielLongNullable` BIGINT(20), 
-  `ByteNullable` TINYINT(3) UNSIGNED, 
-  `UShortNullable` SMALLINT(5) UNSIGNED, 
-  `UIntNullable` INT(10) UNSIGNED, 
-  `ULongNullable` BIGINT(20) UNSIGNED, 
-  `DoubleNullable` DOUBLE, 
-  `FloatNullable` FLOAT, 
-  `DecimalNullable` DECIMAL(10,2), 
-  `TimeSpanNullable` TIME, 
-  `DateTimeNullable` DATETIME, 
-  `GuidNullable` VARCHAR(36), 
-  `Point` POINT, 
-  `LineString` LINESTRING, 
-  `Polygon` POLYGON, 
-  `MultiPoint` MULTIPOINT, 
-  `MultiLineString` MULTILINESTRING, 
-  `MultiPolygon` MULTIPOLYGON, 
-  `Enum1` ENUM('E1','E2','E3') NOT NULL, 
-  `Enum1Nullable` ENUM('E1','E2','E3'), 
-  `Enum2` SET('F1','F2','F3') NOT NULL, 
-  `Enum2Nullable` SET('F1','F2','F3'), 
-  PRIMARY KEY (`Id`)
-) Engine=InnoDB;
-", sql);
-            }
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             //sql = g.oracle.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -239,7 +188,17 @@ namespace FreeSql.Tests.Odbc.Oracle
         public void CurdAllField()
         {
             var item = new TableAllType { };
-            item.Id = (int)insert.AppendData(item).ExecuteIdentity();
+            for (var a = 0; a < 100; a++)
+            {
+                try //ERROR [23000] [Oracle][ODBC][Ora]ORA-00001: 违反唯一约束条件 (1ODBC.1ODBC_TB_ALLTYPE_pk2)
+                {
+                    item.Id = (int)insert.AppendData(item).ExecuteIdentity();
+                    break;
+                }
+                catch
+                {
+                }
+            }
 
             var newitem = select.Where(a => a.Id == item.Id).ToOne();
 
@@ -271,6 +230,7 @@ namespace FreeSql.Tests.Odbc.Oracle
                 Short = short.MaxValue,
                 ShortNullable = short.MinValue,
                 String = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                Char = 'X',
                 TimeSpan = TimeSpan.FromSeconds(999),
                 TimeSpanNullable = TimeSpan.FromSeconds(60),
                 UInt = uint.MaxValue,
@@ -288,10 +248,12 @@ namespace FreeSql.Tests.Odbc.Oracle
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -322,6 +284,7 @@ namespace FreeSql.Tests.Odbc.Oracle
             public DateTime DateTimeOffSet { get; set; }
             public byte[] Bytes { get; set; }
             public string String { get; set; }
+            public char Char { get; set; }
             public Guid Guid { get; set; }
 
             public bool? BoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/PostgreSQL/PostgreSQLCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/PostgreSQL/PostgreSQLCodeFirstTest.cs
index d46ae080..99312f7e 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/PostgreSQL/PostgreSQLCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/PostgreSQL/PostgreSQLCodeFirstTest.cs
@@ -105,8 +105,8 @@ namespace FreeSql.Tests.Odbc.PostgreSQL
         public void AddField()
         {
             var sql = g.pgsql.CodeFirst.GetComparisonDDLStatements<TopicAddField>();
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             g.pgsql.Select<TopicAddField>();
-
             var id = g.pgsql.Insert<TopicAddField>().AppendData(new TopicAddField { }).ExecuteIdentity();
         }
 
@@ -184,6 +184,7 @@ namespace FreeSql.Tests.Odbc.PostgreSQL
                 testFieldShort = short.MaxValue,
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 testFieldTimeSpan = TimeSpan.FromDays(1),
                 testFieldTimeSpanNullable = TimeSpan.FromSeconds(90),
                 testFieldUInt = uint.MaxValue,
@@ -202,10 +203,12 @@ namespace FreeSql.Tests.Odbc.PostgreSQL
             var item3 = insert.AppendData(item2).ExecuteInserted().First();
             var newitem2 = select.Where(a => a.Id == item3.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item3 = insert.NoneParameter().AppendData(item2).ExecuteInserted().First();
             newitem2 = select.Where(a => a.Id == item3.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -233,6 +236,7 @@ namespace FreeSql.Tests.Odbc.PostgreSQL
             public DateTime testFieldDateTime { get; set; }
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
 
             public bool? testFieldBoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/SqlServer/SqlServerCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/SqlServer/SqlServerCodeFirstTest.cs
index 48bfefbd..9bb412ea 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/SqlServer/SqlServerCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/SqlServer/SqlServerCodeFirstTest.cs
@@ -166,9 +166,8 @@ namespace FreeSql.Tests.Odbc.SqlServer
         [Fact]
         public void GetComparisonDDLStatements()
         {
-
             var sql = g.sqlserver.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             sql = g.sqlserver.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -214,6 +213,7 @@ namespace FreeSql.Tests.Odbc.SqlServer
                 testFieldShort = short.MaxValue,
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 testFieldTimeSpan = TimeSpan.FromSeconds(999),
                 testFieldTimeSpanNullable = TimeSpan.FromSeconds(30),
                 testFieldUInt = uint.MaxValue,
@@ -234,10 +234,12 @@ namespace FreeSql.Tests.Odbc.SqlServer
             var item3 = insert.AppendData(item2).ExecuteInserted();
             var newitem2 = select.Where(a => a.Id == item3[0].Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item3 = insert.NoneParameter().AppendData(item2).ExecuteInserted();
             newitem2 = select.Where(a => a.Id == item3[0].Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -367,6 +369,10 @@ namespace FreeSql.Tests.Odbc.SqlServer
             public string TestFieldString { get; set; }
 
 
+            [JsonProperty, Column(Name = "testFieldChar", DbType = "char(1)", IsNullable = true)]
+            public char testFieldChar { get; set; }
+
+
             [JsonProperty, Column(Name = "testFieldTimeSpan", DbType = "time")]
             public TimeSpan TestFieldTimeSpan { get; set; }
 
@@ -427,6 +433,7 @@ namespace FreeSql.Tests.Odbc.SqlServer
             public DateTimeOffset testFieldDateTimeOffset { get; set; }
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
 
             public bool? testFieldBoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.PostgreSQL.NetTopologySuite/PostgreSQL/PostgreSQLCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.PostgreSQL.NetTopologySuite/PostgreSQL/PostgreSQLCodeFirstTest.cs
index 59fa573c..5fd6226e 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.PostgreSQL.NetTopologySuite/PostgreSQL/PostgreSQLCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.PostgreSQL.NetTopologySuite/PostgreSQL/PostgreSQLCodeFirstTest.cs
@@ -22,8 +22,8 @@ namespace FreeSql.Tests.PostgreSQL.NetTopologySuite
         [Fact]
         public void GetComparisonDDLStatements()
         {
-
             var sql = g.pgsql.CodeFirst.GetComparisonDDLStatements<TableAllType>();
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             g.pgsql.Select<TableAllType>();
         }
 
@@ -230,6 +230,7 @@ namespace FreeSql.Tests.PostgreSQL.NetTopologySuite
                 testFieldShortArrayNullable = new short?[] { 1, 2, 3, null, 4, 5 },
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 testFieldStringArray = new[] { "我是中国人String1", "我是中国人String2", null, "我是中国人String3" },
                 testFieldTimeSpan = TimeSpan.FromDays(1),
                 testFieldTimeSpanArray = new[] { TimeSpan.FromDays(1), TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(60) },
@@ -262,10 +263,12 @@ namespace FreeSql.Tests.PostgreSQL.NetTopologySuite
             var item3 = insert.AppendData(item2).ExecuteInserted().First();
             var newitem2 = select.Where(a => a.Id == item3.Id && object.Equals(a.testFieldJToken["a"], "1")).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item3 = insert.NoneParameter().AppendData(item2).ExecuteInserted().First();
             newitem2 = select.Where(a => a.Id == item3.Id && object.Equals(a.testFieldJToken["a"], "1")).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -296,6 +299,7 @@ namespace FreeSql.Tests.PostgreSQL.NetTopologySuite
 
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
             public NpgsqlPoint testFieldNpgsqlPoint { get; set; }
             public NpgsqlLine testFieldNpgsqlLine { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests/Dameng/DamengCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/Dameng/DamengCodeFirstTest.cs
index 4369ea87..de3a6c69 100644
--- a/FreeSql.Tests/FreeSql.Tests/Dameng/DamengCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/Dameng/DamengCodeFirstTest.cs
@@ -247,59 +247,8 @@ namespace FreeSql.Tests.Dameng
         [Fact]
         public void GetComparisonDDLStatements()
         {
-
             var sql = g.dameng.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-            if (string.IsNullOrEmpty(sql) == false)
-            {
-                Assert.Equal(@"CREATE TABLE IF NOT EXISTS `cccddd`.`tb_alltype` ( 
-  `Id` INT(11) NOT NULL AUTO_INCREMENT, 
-  `Bool` BIT(1) NOT NULL, 
-  `SByte` TINYINT(3) NOT NULL, 
-  `Short` SMALLINT(6) NOT NULL, 
-  `Int` INT(11) NOT NULL, 
-  `Long` BIGINT(20) NOT NULL, 
-  `Byte` TINYINT(3) UNSIGNED NOT NULL, 
-  `UShort` SMALLINT(5) UNSIGNED NOT NULL, 
-  `UInt` INT(10) UNSIGNED NOT NULL, 
-  `ULong` BIGINT(20) UNSIGNED NOT NULL, 
-  `Double` DOUBLE NOT NULL, 
-  `Float` FLOAT NOT NULL, 
-  `Decimal` DECIMAL(10,2) NOT NULL, 
-  `TimeSpan` TIME NOT NULL, 
-  `DateTime` DATETIME NOT NULL, 
-  `Bytes` VARBINARY(255), 
-  `String` VARCHAR(255), 
-  `Guid` VARCHAR(36), 
-  `BoolNullable` BIT(1), 
-  `SByteNullable` TINYINT(3), 
-  `ShortNullable` SMALLINT(6), 
-  `IntNullable` INT(11), 
-  `testFielLongNullable` BIGINT(20), 
-  `ByteNullable` TINYINT(3) UNSIGNED, 
-  `UShortNullable` SMALLINT(5) UNSIGNED, 
-  `UIntNullable` INT(10) UNSIGNED, 
-  `ULongNullable` BIGINT(20) UNSIGNED, 
-  `DoubleNullable` DOUBLE, 
-  `FloatNullable` FLOAT, 
-  `DecimalNullable` DECIMAL(10,2), 
-  `TimeSpanNullable` TIME, 
-  `DateTimeNullable` DATETIME, 
-  `GuidNullable` VARCHAR(36), 
-  `Point` POINT, 
-  `LineString` LINESTRING, 
-  `Polygon` POLYGON, 
-  `MultiPoint` MULTIPOINT, 
-  `MultiLineString` MULTILINESTRING, 
-  `MultiPolygon` MULTIPOLYGON, 
-  `Enum1` ENUM('E1','E2','E3') NOT NULL, 
-  `Enum1Nullable` ENUM('E1','E2','E3'), 
-  `Enum2` SET('F1','F2','F3') NOT NULL, 
-  `Enum2Nullable` SET('F1','F2','F3'), 
-  PRIMARY KEY (`Id`)
-) Engine=InnoDB;
-", sql);
-            }
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             //sql = g.dameng.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -338,6 +287,7 @@ namespace FreeSql.Tests.Dameng
                 Short = short.MaxValue,
                 ShortNullable = short.MinValue,
                 String = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                Char = 'X',
                 TimeSpan = TimeSpan.FromSeconds(999),
                 TimeSpanNullable = TimeSpan.FromSeconds(60),
                 UInt = uint.MaxValue,
@@ -355,10 +305,12 @@ namespace FreeSql.Tests.Dameng
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -389,6 +341,7 @@ namespace FreeSql.Tests.Dameng
             public DateTime DateTimeOffSet { get; set; }
             public byte[] Bytes { get; set; }
             public string String { get; set; }
+            public char Char { get; set; }
             public Guid Guid { get; set; }
 
             public bool? BoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests/MsAccess/MsAccessCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/MsAccess/MsAccessCodeFirstTest.cs
index 5c2dc9c0..622c63d3 100644
--- a/FreeSql.Tests/FreeSql.Tests/MsAccess/MsAccessCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/MsAccess/MsAccessCodeFirstTest.cs
@@ -177,54 +177,7 @@ namespace FreeSql.Tests.MsAccess
         {
 
             var sql = g.msaccess.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-            if (string.IsNullOrEmpty(sql) == false)
-            {
-                Assert.Equal(@"CREATE TABLE [tb_alltype] (  
-  [Id] AUTOINCREMENT, 
-  [Bool] BIT NOT NULL, 
-  [SByte] DECIMAL(3,0) NOT NULL, 
-  [Short] DECIMAL(6,0) NOT NULL, 
-  [Int] DECIMAL(11,0) NOT NULL, 
-  [Long] DECIMAL(20,0) NOT NULL, 
-  [Byte] DECIMAL(3,0) NOT NULL, 
-  [UShort] DECIMAL(5,0) NOT NULL, 
-  [UInt] DECIMAL(10,0) NOT NULL, 
-  [ULong] DECIMAL(20,0) NOT NULL, 
-  [Double] DOUBLE NOT NULL, 
-  [Float] SINGLE NOT NULL, 
-  [Decimal] DECIMAL(10,2) NOT NULL, 
-  [TimeSpan] TIME NOT NULL, 
-  [DateTime] DATETIME NOT NULL, 
-  [DateTimeOffSet] DATETIME NOT NULL, 
-  [Bytes] BINARY(255), 
-  [String] VARCHAR(255), 
-  [Guid] VARCHAR(36) NOT NULL, 
-  [BoolNullable] BIT, 
-  [SByteNullable] DECIMAL(3,0), 
-  [ShortNullable] DECIMAL(6,0), 
-  [IntNullable] DECIMAL(11,0), 
-  [testFielLongNullable] DECIMAL(20,0), 
-  [ByteNullable] DECIMAL(3,0), 
-  [UShortNullable] DECIMAL(5,0), 
-  [UIntNullable] DECIMAL(10,0), 
-  [ULongNullable] DECIMAL(20,0), 
-  [DoubleNullable] DOUBLE, 
-  [FloatNullable] SINGLE, 
-  [DecimalNullable] DECIMAL(10,2), 
-  [TimeSpanNullable] TIME, 
-  [DateTimeNullable] DATETIME, 
-  [DateTimeOffSetNullable] DATETIME, 
-  [GuidNullable] VARCHAR(36), 
-  [Enum1] DECIMAL(11,0) NOT NULL, 
-  [Enum1Nullable] DECIMAL(11,0), 
-  [Enum2] DECIMAL(20,0) NOT NULL, 
-  [Enum2Nullable] DECIMAL(20,0), 
-  PRIMARY KEY ([Id])
-) 
-;
-", sql);
-            }
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             //sql = g.msaccess.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -267,6 +220,7 @@ namespace FreeSql.Tests.MsAccess
                 Short = short.MaxValue,
                 ShortNullable = short.MinValue,
                 String = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                Char = 'X',
                 TimeSpan = TimeSpan.FromSeconds(999),
                 TimeSpanNullable = TimeSpan.FromSeconds(60),
                 UInt = uint.MaxValue,
@@ -280,10 +234,12 @@ namespace FreeSql.Tests.MsAccess
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -318,6 +274,7 @@ namespace FreeSql.Tests.MsAccess
 
             public byte[] Bytes { get; set; }
             public string String { get; set; }
+            public char Char { get; set; }
             public Guid Guid { get; set; }
 
             public bool? BoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs
index 346a806c..463a101e 100644
--- a/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs
@@ -281,57 +281,7 @@ namespace FreeSql.Tests.MySql
         {
 
             var sql = g.mysql.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-            if (string.IsNullOrEmpty(sql) == false)
-            {
-                Assert.Equal(@"CREATE TABLE IF NOT EXISTS `cccddd`.`tb_alltype` ( 
-  `Id` INT(11) NOT NULL AUTO_INCREMENT, 
-  `testFieldBool` BIT(1) NOT NULL, 
-  `testFieldSByte` TINYINT(3) NOT NULL, 
-  `testFieldShort` SMALLINT(6) NOT NULL, 
-  `testFieldInt` INT(11) NOT NULL, 
-  `testFieldLong` BIGINT(20) NOT NULL, 
-  `testFieldByte` TINYINT(3) UNSIGNED NOT NULL, 
-  `testFieldUShort` SMALLINT(5) UNSIGNED NOT NULL, 
-  `testFieldUInt` INT(10) UNSIGNED NOT NULL, 
-  `testFieldULong` BIGINT(20) UNSIGNED NOT NULL, 
-  `testFieldDouble` DOUBLE NOT NULL, 
-  `testFieldFloat` FLOAT NOT NULL, 
-  `testFieldDecimal` DECIMAL(10,2) NOT NULL, 
-  `testFieldTimeSpan` TIME NOT NULL, 
-  `testFieldDateTime` DATETIME(3) NOT NULL, 
-  `testFieldBytes` VARBINARY(255), 
-  `testFieldString` VARCHAR(255), 
-  `testFieldGuid` VARCHAR(36), 
-  `testFieldBoolNullable` BIT(1), 
-  `testFieldSByteNullable` TINYINT(3), 
-  `testFieldShortNullable` SMALLINT(6), 
-  `testFieldIntNullable` INT(11), 
-  `testFielLongNullable` BIGINT(20), 
-  `testFieldByteNullable` TINYINT(3) UNSIGNED, 
-  `testFieldUShortNullable` SMALLINT(5) UNSIGNED, 
-  `testFieldUIntNullable` INT(10) UNSIGNED, 
-  `testFieldULongNullable` BIGINT(20) UNSIGNED, 
-  `testFieldDoubleNullable` DOUBLE, 
-  `testFieldFloatNullable` FLOAT, 
-  `testFieldDecimalNullable` DECIMAL(10,2), 
-  `testFieldTimeSpanNullable` TIME, 
-  `testFieldDateTimeNullable` DATETIME(3), 
-  `testFieldGuidNullable` VARCHAR(36), 
-  `testFieldPoint` POINT, 
-  `testFieldLineString` LINESTRING, 
-  `testFieldPolygon` POLYGON, 
-  `testFieldMultiPoint` MULTIPOINT, 
-  `testFieldMultiLineString` MULTILINESTRING, 
-  `testFieldMultiPolygon` MULTIPOLYGON, 
-  `testFieldEnum1` ENUM('E1','E2','E3') NOT NULL, 
-  `testFieldEnum1Nullable` ENUM('E1','E2','E3'), 
-  `testFieldEnum2` SET('F1','F2','F3') NOT NULL, 
-  `testFieldEnum2Nullable` SET('F1','F2','F3'), 
-  PRIMARY KEY (`Id`)
-) Engine=InnoDB;
-", sql);
-            }
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             sql = g.mysql.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -397,6 +347,7 @@ namespace FreeSql.Tests.MySql
                 testFieldShort = short.MaxValue,
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 testFieldTimeSpan = TimeSpan.FromSeconds(999),
                 testFieldTimeSpanNullable = TimeSpan.FromSeconds(60),
                 testFieldUInt = uint.MaxValue,
@@ -416,10 +367,12 @@ namespace FreeSql.Tests.MySql
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -566,6 +519,10 @@ namespace FreeSql.Tests.MySql
             public string TestFieldString { get; set; }
 
 
+            [JsonProperty, Column(Name = "testFieldChar", DbType = "char(1)", IsNullable = true)]
+            public char testFieldChar { get; set; }
+
+
             [JsonProperty, Column(Name = "testFieldTimeSpan", DbType = "time")]
             public TimeSpan TestFieldTimeSpan { get; set; }
 
@@ -670,6 +627,7 @@ namespace FreeSql.Tests.MySql
 
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
 
             public bool? testFieldBoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests/Oracle/OracleCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/Oracle/OracleCodeFirstTest.cs
index 7e334513..5774f0a6 100644
--- a/FreeSql.Tests/FreeSql.Tests/Oracle/OracleCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/Oracle/OracleCodeFirstTest.cs
@@ -279,57 +279,7 @@ namespace FreeSql.Tests.Oracle
         {
 
             var sql = g.oracle.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-            if (string.IsNullOrEmpty(sql) == false)
-            {
-                Assert.Equal(@"CREATE TABLE IF NOT EXISTS `cccddd`.`tb_alltype` ( 
-  `Id` INT(11) NOT NULL AUTO_INCREMENT, 
-  `Bool` BIT(1) NOT NULL, 
-  `SByte` TINYINT(3) NOT NULL, 
-  `Short` SMALLINT(6) NOT NULL, 
-  `Int` INT(11) NOT NULL, 
-  `Long` BIGINT(20) NOT NULL, 
-  `Byte` TINYINT(3) UNSIGNED NOT NULL, 
-  `UShort` SMALLINT(5) UNSIGNED NOT NULL, 
-  `UInt` INT(10) UNSIGNED NOT NULL, 
-  `ULong` BIGINT(20) UNSIGNED NOT NULL, 
-  `Double` DOUBLE NOT NULL, 
-  `Float` FLOAT NOT NULL, 
-  `Decimal` DECIMAL(10,2) NOT NULL, 
-  `TimeSpan` TIME NOT NULL, 
-  `DateTime` DATETIME NOT NULL, 
-  `Bytes` VARBINARY(255), 
-  `String` VARCHAR(255), 
-  `Guid` VARCHAR(36), 
-  `BoolNullable` BIT(1), 
-  `SByteNullable` TINYINT(3), 
-  `ShortNullable` SMALLINT(6), 
-  `IntNullable` INT(11), 
-  `testFielLongNullable` BIGINT(20), 
-  `ByteNullable` TINYINT(3) UNSIGNED, 
-  `UShortNullable` SMALLINT(5) UNSIGNED, 
-  `UIntNullable` INT(10) UNSIGNED, 
-  `ULongNullable` BIGINT(20) UNSIGNED, 
-  `DoubleNullable` DOUBLE, 
-  `FloatNullable` FLOAT, 
-  `DecimalNullable` DECIMAL(10,2), 
-  `TimeSpanNullable` TIME, 
-  `DateTimeNullable` DATETIME, 
-  `GuidNullable` VARCHAR(36), 
-  `Point` POINT, 
-  `LineString` LINESTRING, 
-  `Polygon` POLYGON, 
-  `MultiPoint` MULTIPOINT, 
-  `MultiLineString` MULTILINESTRING, 
-  `MultiPolygon` MULTIPOLYGON, 
-  `Enum1` ENUM('E1','E2','E3') NOT NULL, 
-  `Enum1Nullable` ENUM('E1','E2','E3'), 
-  `Enum2` SET('F1','F2','F3') NOT NULL, 
-  `Enum2Nullable` SET('F1','F2','F3'), 
-  PRIMARY KEY (`Id`)
-) Engine=InnoDB;
-", sql);
-            }
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             //sql = g.oracle.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -372,6 +322,7 @@ namespace FreeSql.Tests.Oracle
                 Short = short.MaxValue,
                 ShortNullable = short.MinValue,
                 String = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                Char = 'X',
                 TimeSpan = TimeSpan.FromSeconds(999),
                 TimeSpanNullable = TimeSpan.FromSeconds(60),
                 UInt = uint.MaxValue,
@@ -389,10 +340,12 @@ namespace FreeSql.Tests.Oracle
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -427,6 +380,7 @@ namespace FreeSql.Tests.Oracle
 
             public byte[] Bytes { get; set; }
             public string String { get; set; }
+            public char Char { get; set; }
             public Guid Guid { get; set; }
 
             public bool? BoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests/PostgreSQL/PostgreSQLCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/PostgreSQL/PostgreSQLCodeFirstTest.cs
index 094a3afa..f4ee21d6 100644
--- a/FreeSql.Tests/FreeSql.Tests/PostgreSQL/PostgreSQLCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/PostgreSQL/PostgreSQLCodeFirstTest.cs
@@ -145,8 +145,8 @@ namespace FreeSql.Tests.PostgreSQL
         public void AddField()
         {
             var sql = g.pgsql.CodeFirst.GetComparisonDDLStatements<TopicAddField>();
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             g.pgsql.Select<TopicAddField>();
-
             var id = g.pgsql.Insert<TopicAddField>().AppendData(new TopicAddField { }).ExecuteIdentity();
         }
 
@@ -388,6 +388,7 @@ namespace FreeSql.Tests.PostgreSQL
                 testFieldShortArrayNullable = new short?[] { 1, 2, 3, null, 4, 5 },
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 testFieldStringArray = new[] { "我是中国人String1", "我是中国人String2", null, "我是中国人String3" },
                 testFieldTimeSpan = TimeSpan.FromDays(1),
                 testFieldTimeSpanArray = new[] { TimeSpan.FromDays(1), TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(60) },
@@ -420,10 +421,12 @@ namespace FreeSql.Tests.PostgreSQL
             var item3 = insert.AppendData(item2).ExecuteInserted().First();
             var newitem2 = select.Where(a => a.Id == item3.Id && object.Equals(a.testFieldJToken["a"], "1")).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item3 = insert.NoneParameter().AppendData(item2).ExecuteInserted().First();
             newitem2 = select.Where(a => a.Id == item3.Id && object.Equals(a.testFieldJToken["a"], "1")).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -454,6 +457,7 @@ namespace FreeSql.Tests.PostgreSQL
 
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
             public NpgsqlPoint testFieldNpgsqlPoint { get; set; }
             public NpgsqlLine testFieldNpgsqlLine { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests/ShenTong/ShenTongCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/ShenTong/ShenTongCodeFirstTest.cs
index 6c6f93d5..2716341e 100644
--- a/FreeSql.Tests/FreeSql.Tests/ShenTong/ShenTongCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/ShenTong/ShenTongCodeFirstTest.cs
@@ -143,8 +143,8 @@ namespace FreeSql.Tests.ShenTong
         [Fact]
         public void GetComparisonDDLStatements()
         {
-
             var sql = g.shentong.CodeFirst.GetComparisonDDLStatements<TableAllType>();
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             g.shentong.Select<TableAllType>();
         }
 
@@ -217,6 +217,7 @@ namespace FreeSql.Tests.ShenTong
                 //testFieldShortArrayNullable = new short?[] { 1, 2, 3, null, 4, 5 },
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 //testFieldStringArray = new[] { "我是中国人String1", "我是中国人String2", null, "我是中国人String3" },
                 testFieldTimeSpan = TimeSpan.FromHours(10),
                 //testFieldTimeSpanArray = new[] { TimeSpan.FromHours(10), TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(60) },
@@ -245,10 +246,12 @@ namespace FreeSql.Tests.ShenTong
             var item3 = insert.AppendData(item2).ExecuteInserted().First();
             var newitem2 = select.Where(a => a.Id == item3.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item3 = insert.NoneParameter().AppendData(item2).ExecuteInserted().First();
             newitem2 = select.Where(a => a.Id == item3.Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -279,6 +282,7 @@ namespace FreeSql.Tests.ShenTong
 
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
 
             public bool? testFieldBoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests/SqlServer/SqlServerCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/SqlServer/SqlServerCodeFirstTest.cs
index 20723d8b..34c6c2e4 100644
--- a/FreeSql.Tests/FreeSql.Tests/SqlServer/SqlServerCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/SqlServer/SqlServerCodeFirstTest.cs
@@ -202,9 +202,8 @@ namespace FreeSql.Tests.SqlServer
         [Fact]
         public void GetComparisonDDLStatements()
         {
-
             var sql = g.sqlserver.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             sql = g.sqlserver.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -250,6 +249,7 @@ namespace FreeSql.Tests.SqlServer
                 testFieldShort = short.MaxValue,
                 testFieldShortNullable = short.MinValue,
                 testFieldString = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                testFieldChar = 'X',
                 testFieldTimeSpan = TimeSpan.FromSeconds(999),
                 testFieldTimeSpanNullable = TimeSpan.FromSeconds(30),
                 testFieldUInt = uint.MaxValue,
@@ -270,10 +270,12 @@ namespace FreeSql.Tests.SqlServer
             var item3 = insert.AppendData(item2).ExecuteInserted();
             var newitem2 = select.Where(a => a.Id == item3[0].Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             item3 = insert.NoneParameter().AppendData(item2).ExecuteInserted();
             newitem2 = select.Where(a => a.Id == item3[0].Id).ToOne();
             Assert.Equal(item2.testFieldString, newitem2.testFieldString);
+            Assert.Equal(item2.testFieldChar, newitem2.testFieldChar);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -403,6 +405,10 @@ namespace FreeSql.Tests.SqlServer
             public string TestFieldString { get; set; }
 
 
+            [JsonProperty, Column(Name = "testFieldChar", DbType = "char(1)", IsNullable = true)]
+            public char testFieldChar { get; set; }
+
+
             [JsonProperty, Column(Name = "testFieldTimeSpan", DbType = "time")]
             public TimeSpan TestFieldTimeSpan { get; set; }
 
@@ -467,6 +473,7 @@ namespace FreeSql.Tests.SqlServer
 
             public byte[] testFieldBytes { get; set; }
             public string testFieldString { get; set; }
+            public char testFieldChar { get; set; }
             public Guid testFieldGuid { get; set; }
 
             public bool? testFieldBoolNullable { get; set; }
diff --git a/FreeSql.Tests/FreeSql.Tests/Sqlite/SqliteCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/Sqlite/SqliteCodeFirstTest.cs
index d3634ce2..9f00a265 100644
--- a/FreeSql.Tests/FreeSql.Tests/Sqlite/SqliteCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/Sqlite/SqliteCodeFirstTest.cs
@@ -239,53 +239,7 @@ namespace FreeSql.Tests.Sqlite
         {
 
             var sql = g.sqlite.CodeFirst.GetComparisonDDLStatements<TableAllType>();
-            if (string.IsNullOrEmpty(sql) == false)
-            {
-                Assert.Equal(@"CREATE TABLE IF NOT EXISTS ""main"".""tb_alltype"" ( 
-  ""Id"" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, 
-  ""Bool"" BOOLEAN NOT NULL, 
-  ""SByte"" SMALLINT NOT NULL, 
-  ""Short"" SMALLINT NOT NULL, 
-  ""Int"" INTEGER NOT NULL, 
-  ""Long"" INTEGER NOT NULL, 
-  ""Byte"" INT2 NOT NULL, 
-  ""UShort"" UNSIGNED NOT NULL, 
-  ""UInt"" DECIMAL(10,0) NOT NULL, 
-  ""ULong"" DECIMAL(21,0) NOT NULL, 
-  ""Double"" DOUBLE NOT NULL, 
-  ""Float"" FLOAT NOT NULL, 
-  ""Decimal"" DECIMAL(10,2) NOT NULL, 
-  ""TimeSpan"" BIGINT NOT NULL, 
-  ""DateTime"" DATETIME NOT NULL, 
-  ""DateTimeOffSet"" DATETIME NOT NULL, 
-  ""Bytes"" BLOB, 
-  ""String"" NVARCHAR(255), 
-  ""Guid"" CHARACTER(36) NOT NULL, 
-  ""BoolNullable"" BOOLEAN, 
-  ""SByteNullable"" SMALLINT, 
-  ""ShortNullable"" SMALLINT, 
-  ""IntNullable"" INTEGER, 
-  ""testFielLongNullable"" INTEGER, 
-  ""ByteNullable"" INT2, 
-  ""UShortNullable"" UNSIGNED, 
-  ""UIntNullable"" DECIMAL(10,0), 
-  ""ULongNullable"" DECIMAL(21,0), 
-  ""DoubleNullable"" DOUBLE, 
-  ""FloatNullable"" FLOAT, 
-  ""DecimalNullable"" DECIMAL(10,2), 
-  ""TimeSpanNullable"" BIGINT, 
-  ""DateTimeNullable"" DATETIME, 
-  ""DateTimeOffSetNullable"" DATETIME, 
-  ""GuidNullable"" CHARACTER(36), 
-  ""Enum1"" MEDIUMINT NOT NULL, 
-  ""Enum1Nullable"" MEDIUMINT, 
-  ""Enum2"" BIGINT NOT NULL, 
-  ""Enum2Nullable"" BIGINT
-) 
-;
-", sql);
-            }
-
+            Assert.True(string.IsNullOrEmpty(sql)); //测试运行两次后
             //sql = g.Sqlite.CodeFirst.GetComparisonDDLStatements<Tb_alltype>();
         }
 
@@ -328,6 +282,7 @@ namespace FreeSql.Tests.Sqlite
                 Short = short.MaxValue,
                 ShortNullable = short.MinValue,
                 String = "我是中国人string'\\?!@#$%^&*()_+{}}{~?><<>",
+                Char = 'X',
                 TimeSpan = TimeSpan.FromSeconds(999),
                 TimeSpanNullable = TimeSpan.FromSeconds(60),
                 UInt = uint.MaxValue,
@@ -341,10 +296,12 @@ namespace FreeSql.Tests.Sqlite
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             item2.Id = (int)insert.NoneParameter().AppendData(item2).ExecuteIdentity();
             newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
             Assert.Equal(item2.String, newitem2.String);
+            Assert.Equal(item2.Char, newitem2.Char);
 
             var items = select.ToList();
             var itemstb = select.ToDataTable();
@@ -379,6 +336,7 @@ namespace FreeSql.Tests.Sqlite
 
             public byte[] Bytes { get; set; }
             public string String { get; set; }
+            public char Char { get; set; }
             public Guid Guid { get; set; }
 
             public bool? BoolNullable { get; set; }
diff --git a/FreeSql/Internal/UtilsExpressionTree.cs b/FreeSql/Internal/UtilsExpressionTree.cs
index 272e09e7..e9f4d453 100644
--- a/FreeSql/Internal/UtilsExpressionTree.cs
+++ b/FreeSql/Internal/UtilsExpressionTree.cs
@@ -451,6 +451,7 @@ namespace FreeSql.Internal
                 var m = Regex.Match(col.Attribute.DbType, ltp);
                 if (m.Success == false) continue;
                 var sizeStr = m.Groups[1].Value.Trim();
+                if (sizeStr.EndsWith(" BYTE") || sizeStr.EndsWith(" CHAR")) sizeStr = sizeStr.Remove(sizeStr.Length - 5); //ORACLE
                 if (string.Compare(sizeStr, "max", true) == 0)
                 {
                     col.DbSize = -1;
@@ -1257,6 +1258,7 @@ namespace FreeSql.Internal
             [typeof(DateTimeOffset)] = true,
             [typeof(byte[])] = true,
             [typeof(string)] = true,
+            [typeof(char)] = true,
             [typeof(Guid)] = true,
             //[typeof(MygisPoint)] = true,
             //[typeof(MygisLineString)] = true,
@@ -1719,6 +1721,11 @@ namespace FreeSql.Internal
             if (bytes == null) return Guid.Empty;
             return Guid.TryParse(BitConverter.ToString(bytes, 0, Math.Min(bytes.Length, 36)).Replace("-", ""), out var tryguid) ? tryguid : Guid.Empty;
         }
+        static char StringToChar(string str)
+        {
+            if (string.IsNullOrEmpty(str)) return default(char);
+            return str.ToCharArray(0, 1)[0];
+        }
 
         static ConcurrentDictionary<Type, ConcurrentDictionary<Type, Func<object, object>>> _dicGetDataReaderValue = new ConcurrentDictionary<Type, ConcurrentDictionary<Type, Func<object, object>>>();
         static MethodInfo MethodArrayGetValue = typeof(Array).GetMethod("GetValue", new[] { typeof(int) });
@@ -1749,6 +1756,8 @@ namespace FreeSql.Internal
         static Encoding DefaultEncoding = Encoding.UTF8;
         static MethodInfo MethodEncodingGetBytes = typeof(Encoding).GetMethod("GetBytes", new[] { typeof(string) });
         static MethodInfo MethodEncodingGetString = typeof(Encoding).GetMethod("GetString", new[] { typeof(byte[]) });
+        static MethodInfo MethodStringToCharArray = typeof(string).GetMethod("ToCharArray", new Type[0]);
+        static MethodInfo MethodStringToChar = typeof(Utils).GetMethod("StringToChar", BindingFlags.NonPublic | BindingFlags.Static, null, new[] { typeof(string) }, null);
         static MethodInfo MethodGuidToBytes = typeof(Utils).GetMethod("GuidToBytes", BindingFlags.NonPublic | BindingFlags.Static, null, new[] { typeof(Guid) }, null);
         static MethodInfo MethodBytesToGuid = typeof(Utils).GetMethod("BytesToGuid", BindingFlags.NonPublic | BindingFlags.Static, null, new[] { typeof(byte[]) }, null);
 
@@ -1760,21 +1769,35 @@ namespace FreeSql.Internal
             var valueExp = Expression.Variable(typeof(object), "locvalue");
             Func<Expression> funcGetExpression = () =>
             {
-                if (type.FullName == "System.Byte[]") return Expression.IfThenElse(
-                    Expression.TypeEqual(valueExp, type),
-                    Expression.Return(returnTarget, valueExp),
-                    Expression.IfThenElse(
-                        Expression.TypeEqual(valueExp, typeof(string)),
-                        Expression.Return(returnTarget, Expression.Call(Expression.Constant(DefaultEncoding), MethodEncodingGetBytes, Expression.Convert(valueExp, typeof(string)))),
-                        Expression.IfThenElse(
-                            Expression.OrElse(Expression.TypeEqual(valueExp, typeof(Guid)), Expression.TypeEqual(valueExp, typeof(Guid?))),
-                            Expression.Return(returnTarget, Expression.Call(MethodGuidToBytes, Expression.Convert(valueExp, typeof(Guid)))),
-                            Expression.Return(returnTarget, Expression.Call(Expression.Constant(DefaultEncoding), MethodEncodingGetBytes, Expression.Call(MethodToString, valueExp)))
-                        )
-                    )
-                );
                 if (type.IsArray)
                 {
+                    switch (type.FullName) 
+                    {
+                        case "System.Byte[]":
+                            return Expression.IfThenElse(
+                                Expression.TypeEqual(valueExp, type),
+                                Expression.Return(returnTarget, valueExp),
+                                Expression.IfThenElse(
+                                    Expression.TypeEqual(valueExp, typeof(string)),
+                                    Expression.Return(returnTarget, Expression.Call(Expression.Constant(DefaultEncoding), MethodEncodingGetBytes, Expression.Convert(valueExp, typeof(string)))),
+                                    Expression.IfThenElse(
+                                        Expression.OrElse(Expression.TypeEqual(valueExp, typeof(Guid)), Expression.TypeEqual(valueExp, typeof(Guid?))),
+                                        Expression.Return(returnTarget, Expression.Call(MethodGuidToBytes, Expression.Convert(valueExp, typeof(Guid)))),
+                                        Expression.Return(returnTarget, Expression.Call(Expression.Constant(DefaultEncoding), MethodEncodingGetBytes, Expression.Call(MethodToString, valueExp)))
+                                    )
+                                )
+                            );
+                        case "System.Char[]":
+                            return Expression.IfThenElse(
+                                Expression.TypeEqual(valueExp, type),
+                                Expression.Return(returnTarget, valueExp),
+                                Expression.IfThenElse(
+                                    Expression.TypeEqual(valueExp, typeof(string)),
+                                    Expression.Return(returnTarget, Expression.Call(Expression.Convert(valueExp, typeof(string)), MethodStringToCharArray)),
+                                    Expression.Return(returnTarget, Expression.Call(Expression.Call(MethodToString, valueExp), MethodStringToCharArray))
+                                )
+                            );
+                    }
                     var elementType = type.GetElementType();
                     var arrNewExp = Expression.Variable(type, "arrNew");
                     var arrExp = Expression.Variable(typeof(Array), "arr");
@@ -1817,14 +1840,6 @@ namespace FreeSql.Internal
                 }
                 var typeOrg = type;
                 if (type.IsNullableType()) type = type.GetGenericArguments().First();
-                if (type.IsEnum)
-                    return Expression.Block(
-                        Expression.IfThenElse(
-                            Expression.Equal(Expression.TypeAs(valueExp, typeof(string)), Expression.Constant(string.Empty)),
-                            Expression.Return(returnTarget, Expression.Convert(Expression.Default(type), typeof(object))),
-                            Expression.Return(returnTarget, Expression.Call(MethodEnumParse, Expression.Constant(type, typeof(Type)), Expression.Call(MethodToString, valueExp), Expression.Constant(true, typeof(bool))))
-                        )
-                    );
                 Expression tryparseExp = null;
                 Expression tryparseBooleanExp = null;
                 ParameterExpression tryparseVarExp = null;
@@ -1860,6 +1875,16 @@ namespace FreeSql.Internal
                                     )
                                }
                            );
+                    case "System.Char":
+                        return Expression.IfThenElse(
+                                Expression.TypeEqual(valueExp, type),
+                                Expression.Return(returnTarget, valueExp),
+                                Expression.IfThenElse(
+                                    Expression.TypeEqual(valueExp, typeof(string)),
+                                    Expression.Return(returnTarget, Expression.Convert(Expression.Call(MethodStringToChar, Expression.Convert(valueExp, typeof(string))), typeof(object))),
+                                    Expression.Return(returnTarget, Expression.Convert(Expression.Call(MethodStringToChar, Expression.Call(MethodToString, valueExp)), typeof(object)))
+                                )
+                            );
                     case "System.SByte":
                         tryparseExp = Expression.Block(
                            new[] { tryparseVarExp = Expression.Variable(typeof(sbyte)) },
@@ -2029,6 +2054,14 @@ namespace FreeSql.Internal
                         );
                         break;
                     default:
+                        if (type.IsEnum)
+                            return Expression.Block(
+                                Expression.IfThenElse(
+                                    Expression.Equal(Expression.TypeAs(valueExp, typeof(string)), Expression.Constant(string.Empty)),
+                                    Expression.Return(returnTarget, Expression.Convert(Expression.Default(type), typeof(object))),
+                                    Expression.Return(returnTarget, Expression.Call(MethodEnumParse, Expression.Constant(type, typeof(Type)), Expression.Call(MethodToString, valueExp), Expression.Constant(true, typeof(bool))))
+                                )
+                            );
                         foreach (var switchFunc in GetDataReaderValueBlockExpressionSwitchTypeFullName)
                         {
                             var switchFuncRet = switchFunc(returnTarget, valueExp, type);
diff --git a/Providers/FreeSql.Provider.Dameng/DamengAdo/DamengAdo.cs b/Providers/FreeSql.Provider.Dameng/DamengAdo/DamengAdo.cs
index af9caf76..68f0c7ed 100644
--- a/Providers/FreeSql.Provider.Dameng/DamengAdo/DamengAdo.cs
+++ b/Providers/FreeSql.Provider.Dameng/DamengAdo/DamengAdo.cs
@@ -41,8 +41,10 @@ namespace FreeSql.Dameng
                 return $"hextoraw('{CommonUtils.BytesSqlRaw(param as byte[])}')";
             else if (param is bool || param is bool?)
                 return (bool)param ? 1 : 0;
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Dameng/DamengCodeFirst.cs b/Providers/FreeSql.Provider.Dameng/DamengCodeFirst.cs
index 6da2899d..2e1736fd 100644
--- a/Providers/FreeSql.Provider.Dameng/DamengCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Dameng/DamengCodeFirst.cs
@@ -42,6 +42,7 @@ namespace FreeSql.Dameng
 
                 { typeof(byte[]).FullName, CsToDb.New(DmDbType.VarBinary, "blob", "blob NULL", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(DmDbType.VarChar, "nvarchar2", "nvarchar2(255) NULL", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(DmDbType.Char, "char", "char(1) NULL", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(DmDbType.Char, "char", "char(36) NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(DmDbType.Char, "char", "char(36) NULL", false, true, null) },
             };
diff --git a/Providers/FreeSql.Provider.MsAccess/MsAccessAdo/MsAccessAdo.cs b/Providers/FreeSql.Provider.MsAccess/MsAccessAdo/MsAccessAdo.cs
index 496e9d1e..a86c5a4f 100644
--- a/Providers/FreeSql.Provider.MsAccess/MsAccessAdo/MsAccessAdo.cs
+++ b/Providers/FreeSql.Provider.MsAccess/MsAccessAdo/MsAccessAdo.cs
@@ -42,8 +42,10 @@ namespace FreeSql.MsAccess
 
             if (param is bool || param is bool?)
                 return (bool)param ? -1 : 0;
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.MsAccess/MsAccessCodeFirst.cs b/Providers/FreeSql.Provider.MsAccess/MsAccessCodeFirst.cs
index dcffefd5..6f419a8e 100644
--- a/Providers/FreeSql.Provider.MsAccess/MsAccessCodeFirst.cs
+++ b/Providers/FreeSql.Provider.MsAccess/MsAccessCodeFirst.cs
@@ -39,6 +39,7 @@ namespace FreeSql.MsAccess
 
                 { typeof(byte[]).FullName, CsToDb.New(OleDbType.VarBinary, "varbinary", "varbinary(255)", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(OleDbType.VarChar, "varchar", "varchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(OleDbType.VarChar, "varchar", "varchar(1)", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(OleDbType.Guid, "varchar", "varchar(36) NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(OleDbType.Guid, "varchar", "varchar(36)", false, true, null) },
             };
diff --git a/Providers/FreeSql.Provider.MySql/MySqlAdo/MySqlAdo.cs b/Providers/FreeSql.Provider.MySql/MySqlAdo/MySqlAdo.cs
index 64427c6a..dd9fdbab 100644
--- a/Providers/FreeSql.Provider.MySql/MySqlAdo/MySqlAdo.cs
+++ b/Providers/FreeSql.Provider.MySql/MySqlAdo/MySqlAdo.cs
@@ -45,8 +45,10 @@ namespace FreeSql.MySql
 
             if (param is bool || param is bool?)
                 return (bool)param ? 1 : 0;
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''").Replace("\\", "\\\\"), "'"); //鍙湁 mysql 闇�瑕佸鐞嗗弽鏂滄潬
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace("\\", "\\\\").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return string.Concat("'", param.ToString().Replace("'", "''").Replace("\\", "\\\\"), "'"); //((Enum)val).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.MySql/MySqlCodeFirst.cs b/Providers/FreeSql.Provider.MySql/MySqlCodeFirst.cs
index 7b997653..45cd3dda 100644
--- a/Providers/FreeSql.Provider.MySql/MySqlCodeFirst.cs
+++ b/Providers/FreeSql.Provider.MySql/MySqlCodeFirst.cs
@@ -45,6 +45,7 @@ namespace FreeSql.MySql
 
                 { typeof(byte[]).FullName, CsToDb.New(MySqlDbType.VarBinary, "varbinary", "varbinary(255)", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(MySqlDbType.VarChar, "varchar", "varchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(MySqlDbType.VarChar, "char", "char(1)", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(MySqlDbType.VarChar, "char", "char(36) NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(MySqlDbType.VarChar, "char", "char(36)", false, true, null) },
 
diff --git a/Providers/FreeSql.Provider.Odbc/Dameng/OdbcDamengAdo/OdbcDamengAdo.cs b/Providers/FreeSql.Provider.Odbc/Dameng/OdbcDamengAdo/OdbcDamengAdo.cs
index 71547169..478dec5e 100644
--- a/Providers/FreeSql.Provider.Odbc/Dameng/OdbcDamengAdo/OdbcDamengAdo.cs
+++ b/Providers/FreeSql.Provider.Odbc/Dameng/OdbcDamengAdo/OdbcDamengAdo.cs
@@ -42,8 +42,10 @@ namespace FreeSql.Odbc.Dameng
                 return $"hextoraw('{CommonUtils.BytesSqlRaw(param as byte[])}')";
             else if (param is bool || param is bool?)
                 return (bool)param ? 1 : 0;
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Odbc/Dameng/OdbcDamengCodeFirst.cs b/Providers/FreeSql.Provider.Odbc/Dameng/OdbcDamengCodeFirst.cs
index 72a18e0a..8fd5f373 100644
--- a/Providers/FreeSql.Provider.Odbc/Dameng/OdbcDamengCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Odbc/Dameng/OdbcDamengCodeFirst.cs
@@ -43,6 +43,7 @@ namespace FreeSql.Odbc.Dameng
 
                 { typeof(byte[]).FullName, CsToDb.New(OdbcType.VarBinary, "blob", "blob NULL", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(OdbcType.NVarChar, "nvarchar2", "nvarchar2(255) NULL", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(OdbcType.Char, "char", "char(1) NULL", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(OdbcType.Char, "char", "char(36) NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(OdbcType.Char, "char", "char(36) NULL", false, true, null) },
             };
diff --git a/Providers/FreeSql.Provider.Odbc/Default/OdbcAdapter.cs b/Providers/FreeSql.Provider.Odbc/Default/OdbcAdapter.cs
index 745091fe..7a9cbfd4 100644
--- a/Providers/FreeSql.Provider.Odbc/Default/OdbcAdapter.cs
+++ b/Providers/FreeSql.Provider.Odbc/Default/OdbcAdapter.cs
@@ -38,6 +38,7 @@ namespace FreeSql.Odbc.Default
         public virtual string MappingOdbcTypeDateTime => "datetime";
         public virtual string MappingOdbcTypeVarBinary => "varbinary";
         public virtual string MappingOdbcTypeVarChar => "nvarchar";
+        public virtual string MappingOdbcTypeChar => "char";
         public virtual string MappingOdbcTypeText => "nvarchar(max)";
         public virtual string MappingOdbcTypeUniqueIdentifier => "uniqueidentifier";
 
diff --git a/Providers/FreeSql.Provider.Odbc/Default/OdbcAdo/OdbcAdo.cs b/Providers/FreeSql.Provider.Odbc/Default/OdbcAdo/OdbcAdo.cs
index eb17053b..ce5ca081 100644
--- a/Providers/FreeSql.Provider.Odbc/Default/OdbcAdo/OdbcAdo.cs
+++ b/Providers/FreeSql.Provider.Odbc/Default/OdbcAdo/OdbcAdo.cs
@@ -45,7 +45,7 @@ namespace FreeSql.Odbc.Default
             else if (param is string)
                 return Adapter.UnicodeStringRawSql(param, mapColumn);
             else if (param is char)
-                return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Odbc/Default/OdbcCodeFirst.cs b/Providers/FreeSql.Provider.Odbc/Default/OdbcCodeFirst.cs
index 5d758171..5e848443 100644
--- a/Providers/FreeSql.Provider.Odbc/Default/OdbcCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Odbc/Default/OdbcCodeFirst.cs
@@ -56,6 +56,7 @@ namespace FreeSql.Odbc.Default
 
                             { typeof(byte[]).FullName, CsToDb.New(OdbcType.VarBinary, _utils.Adapter.MappingOdbcTypeVarBinary, $"{_utils.Adapter.MappingOdbcTypeVarBinary}(255)", false, null, new byte[0]) },
                             { typeof(string).FullName, CsToDb.New(OdbcType.VarChar, _utils.Adapter.MappingOdbcTypeVarChar, $"{_utils.Adapter.MappingOdbcTypeVarChar}(255)", false, null, "") },
+                            { typeof(char).FullName, CsToDb.New(OdbcType.Char, _utils.Adapter.MappingOdbcTypeChar, $"{_utils.Adapter.MappingOdbcTypeChar}(1)", false, null, '\0') },
 
                             { typeof(Guid).FullName, CsToDb.New(OdbcType.UniqueIdentifier, deleteBrackets(_utils.Adapter.MappingOdbcTypeUniqueIdentifier), $"{_utils.Adapter.MappingOdbcTypeUniqueIdentifier} NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(OdbcType.UniqueIdentifier, deleteBrackets(_utils.Adapter.MappingOdbcTypeUniqueIdentifier), _utils.Adapter.MappingOdbcTypeUniqueIdentifier, false, true, null) },
                         };
diff --git a/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESAdo/OdbcKingbaseESAdo.cs b/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESAdo/OdbcKingbaseESAdo.cs
index b647490f..11d37474 100644
--- a/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESAdo/OdbcKingbaseESAdo.cs
+++ b/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESAdo/OdbcKingbaseESAdo.cs
@@ -41,8 +41,10 @@ namespace FreeSql.Odbc.KingbaseES
 
             if (param is bool || param is bool?)
                 return (bool)param ? "'t'" : "'f'";
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESCodeFirst.cs b/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESCodeFirst.cs
index 6ea23cb2..1c75a1e0 100644
--- a/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESCodeFirst.cs
@@ -35,6 +35,7 @@ namespace FreeSql.Odbc.KingbaseES
                 { typeof(decimal).FullName, CsToDb.New(OdbcType.Numeric, "numeric", "numeric(10,2) NOT NULL", false, false, 0) },{ typeof(decimal?).FullName, CsToDb.New(OdbcType.Numeric, "numeric", "numeric(10,2)", false, true, null) },
 
                 { typeof(string).FullName, CsToDb.New(OdbcType.VarChar, "varchar", "varchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(OdbcType.Char, "bpchar", "bpchar(1) NULL", false, null, '\0') },
 
                 { typeof(TimeSpan).FullName, CsToDb.New(OdbcType.Time, "time","time NOT NULL", false, false, 0) },{ typeof(TimeSpan?).FullName, CsToDb.New(OdbcType.Time, "time", "time",false, true, null) },
                 { typeof(DateTime).FullName, CsToDb.New(OdbcType.DateTime, "timestamp", "timestamp NOT NULL", false, false, new DateTime(1970,1,1)) },{ typeof(DateTime?).FullName, CsToDb.New(OdbcType.DateTime, "timestamp", "timestamp", false, true, null) },
diff --git a/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESUtils.cs b/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESUtils.cs
index 56bb6382..9c8d470c 100644
--- a/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESUtils.cs
+++ b/Providers/FreeSql.Provider.Odbc/KingbaseES/OdbcKingbaseESUtils.cs
@@ -35,6 +35,7 @@ namespace FreeSql.Odbc.KingbaseES
             { typeof(ushort).FullName, a => int.Parse(string.Concat(a)) }, { typeof(ushort[]).FullName, a => getParamterArrayValue(typeof(int), a, 0) }, { typeof(ushort?[]).FullName, a => getParamterArrayValue(typeof(int?), a, null) },
             { typeof(byte).FullName, a => short.Parse(string.Concat(a)) }, { typeof(byte[]).FullName, a => getParamterArrayValue(typeof(short), a, 0) }, { typeof(byte?[]).FullName, a => getParamterArrayValue(typeof(short?), a, null) },
             { typeof(sbyte).FullName, a => short.Parse(string.Concat(a)) }, { typeof(sbyte[]).FullName, a => getParamterArrayValue(typeof(short), a, 0) }, { typeof(sbyte?[]).FullName, a => getParamterArrayValue(typeof(short?), a, null) },
+            { typeof(char).FullName, a => string.Concat(a).Replace('\0', ' ').ToCharArray().FirstOrDefault() },
         };
         static object getParamterValue(Type type, object value, int level = 0)
         {
diff --git a/Providers/FreeSql.Provider.Odbc/MySql/OdbcMySqlAdo/OdbcMySqlAdo.cs b/Providers/FreeSql.Provider.Odbc/MySql/OdbcMySqlAdo/OdbcMySqlAdo.cs
index 4b9196ca..b1d7573d 100644
--- a/Providers/FreeSql.Provider.Odbc/MySql/OdbcMySqlAdo/OdbcMySqlAdo.cs
+++ b/Providers/FreeSql.Provider.Odbc/MySql/OdbcMySqlAdo/OdbcMySqlAdo.cs
@@ -41,8 +41,10 @@ namespace FreeSql.Odbc.MySql
 
             if (param is bool || param is bool?)
                 return (bool)param ? 1 : 0;
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''").Replace("\\", "\\\\"), "'"); //鍙湁 mysql 闇�瑕佸鐞嗗弽鏂滄潬
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace("\\", "\\\\").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return string.Concat("'", param.ToString().Replace("'", "''").Replace("\\", "\\\\"), "'"); //((Enum)val).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Odbc/MySql/OdbcMySqlCodeFirst.cs b/Providers/FreeSql.Provider.Odbc/MySql/OdbcMySqlCodeFirst.cs
index 6fc5f92d..e1fb6792 100644
--- a/Providers/FreeSql.Provider.Odbc/MySql/OdbcMySqlCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Odbc/MySql/OdbcMySqlCodeFirst.cs
@@ -41,6 +41,7 @@ namespace FreeSql.Odbc.MySql
 
                 { typeof(byte[]).FullName, CsToDb.New(OdbcType.VarBinary, "varbinary", "varbinary(255)", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(OdbcType.VarChar, "varchar", "varchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(OdbcType.Char, "char", "char(1) NULL", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(OdbcType.VarChar, "char", "char(36) NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(OdbcType.VarChar, "char", "char(36)", false, true, null) },
             };
diff --git a/Providers/FreeSql.Provider.Odbc/Oracle/OdbcOracleAdo/OdbcOracleAdo.cs b/Providers/FreeSql.Provider.Odbc/Oracle/OdbcOracleAdo/OdbcOracleAdo.cs
index 699f2912..e0041666 100644
--- a/Providers/FreeSql.Provider.Odbc/Oracle/OdbcOracleAdo/OdbcOracleAdo.cs
+++ b/Providers/FreeSql.Provider.Odbc/Oracle/OdbcOracleAdo/OdbcOracleAdo.cs
@@ -42,8 +42,10 @@ namespace FreeSql.Odbc.Oracle
                 return $"hextoraw('{CommonUtils.BytesSqlRaw(param as byte[])}')";
             else if (param is bool || param is bool?)
                 return (bool)param ? 1 : 0;
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Odbc/Oracle/OdbcOracleCodeFirst.cs b/Providers/FreeSql.Provider.Odbc/Oracle/OdbcOracleCodeFirst.cs
index fb6f9549..18b7a2cd 100644
--- a/Providers/FreeSql.Provider.Odbc/Oracle/OdbcOracleCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Odbc/Oracle/OdbcOracleCodeFirst.cs
@@ -43,6 +43,7 @@ namespace FreeSql.Odbc.Oracle
 
                 { typeof(byte[]).FullName, CsToDb.New(OdbcType.VarBinary, "blob", "blob NULL", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(OdbcType.NVarChar, "nvarchar2", "nvarchar2(255) NULL", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(OdbcType.Char, "char", "char(1 CHAR) NULL", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(OdbcType.Char, "char", "char(36 CHAR) NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(OdbcType.Char, "char", "char(36 CHAR) NULL", false, true, null) },
             };
diff --git a/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLAdo/OdbcPostgreSQLAdo.cs b/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLAdo/OdbcPostgreSQLAdo.cs
index d37dc5ba..72c196a5 100644
--- a/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLAdo/OdbcPostgreSQLAdo.cs
+++ b/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLAdo/OdbcPostgreSQLAdo.cs
@@ -42,8 +42,10 @@ namespace FreeSql.Odbc.PostgreSQL
 
             if (param is bool || param is bool?)
                 return (bool)param ? "'t'" : "'f'";
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLCodeFirst.cs b/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLCodeFirst.cs
index ee4f79d5..471b4f54 100644
--- a/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLCodeFirst.cs
@@ -33,6 +33,7 @@ namespace FreeSql.Odbc.PostgreSQL
                 { typeof(decimal).FullName, CsToDb.New(OdbcType.Numeric, "numeric", "numeric(10,2) NOT NULL", false, false, 0) },{ typeof(decimal?).FullName, CsToDb.New(OdbcType.Numeric, "numeric", "numeric(10,2)", false, true, null) },
 
                 { typeof(string).FullName, CsToDb.New(OdbcType.VarChar, "varchar", "varchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(OdbcType.Char, "char", "char(1) NULL", false, null, '\0') },
 
                 { typeof(TimeSpan).FullName, CsToDb.New(OdbcType.Time, "time","time NOT NULL", false, false, 0) },{ typeof(TimeSpan?).FullName, CsToDb.New(OdbcType.Time, "time", "time",false, true, null) },
                 { typeof(DateTime).FullName, CsToDb.New(OdbcType.DateTime, "timestamp", "timestamp NOT NULL", false, false, new DateTime(1970,1,1)) },{ typeof(DateTime?).FullName, CsToDb.New(OdbcType.DateTime, "timestamp", "timestamp", false, true, null) },
diff --git a/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLUtils.cs b/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLUtils.cs
index 7a223e82..1182028e 100644
--- a/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLUtils.cs
+++ b/Providers/FreeSql.Provider.Odbc/PostgreSQL/OdbcPostgreSQLUtils.cs
@@ -35,6 +35,7 @@ namespace FreeSql.Odbc.PostgreSQL
             { typeof(ushort).FullName, a => int.Parse(string.Concat(a)) }, { typeof(ushort[]).FullName, a => getParamterArrayValue(typeof(int), a, 0) }, { typeof(ushort?[]).FullName, a => getParamterArrayValue(typeof(int?), a, null) },
             { typeof(byte).FullName, a => short.Parse(string.Concat(a)) }, { typeof(byte[]).FullName, a => getParamterArrayValue(typeof(short), a, 0) }, { typeof(byte?[]).FullName, a => getParamterArrayValue(typeof(short?), a, null) },
             { typeof(sbyte).FullName, a => short.Parse(string.Concat(a)) }, { typeof(sbyte[]).FullName, a => getParamterArrayValue(typeof(short), a, 0) }, { typeof(sbyte?[]).FullName, a => getParamterArrayValue(typeof(short?), a, null) },
+            { typeof(char).FullName, a => string.Concat(a).Replace('\0', ' ').ToCharArray().FirstOrDefault() },
         };
         static object getParamterValue(Type type, object value, int level = 0)
         {
diff --git a/Providers/FreeSql.Provider.Odbc/SqlServer/OdbcSqlServerAdo/OdbcSqlServerAdo.cs b/Providers/FreeSql.Provider.Odbc/SqlServer/OdbcSqlServerAdo/OdbcSqlServerAdo.cs
index 0bba96e3..c6277105 100644
--- a/Providers/FreeSql.Provider.Odbc/SqlServer/OdbcSqlServerAdo/OdbcSqlServerAdo.cs
+++ b/Providers/FreeSql.Provider.Odbc/SqlServer/OdbcSqlServerAdo/OdbcSqlServerAdo.cs
@@ -50,7 +50,7 @@ namespace FreeSql.Odbc.SqlServer
                 return string.Concat("N'", param.ToString().Replace("'", "''"), "'");
             }
             else if (param is char)
-                return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Odbc/SqlServer/OdbcSqlServerCodeFirst.cs b/Providers/FreeSql.Provider.Odbc/SqlServer/OdbcSqlServerCodeFirst.cs
index 8636b79b..a5ea6588 100644
--- a/Providers/FreeSql.Provider.Odbc/SqlServer/OdbcSqlServerCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Odbc/SqlServer/OdbcSqlServerCodeFirst.cs
@@ -41,6 +41,7 @@ namespace FreeSql.Odbc.SqlServer
 
                 { typeof(byte[]).FullName, CsToDb.New(OdbcType.VarBinary, "varbinary", "varbinary(255)", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(OdbcType.NVarChar, "nvarchar", "nvarchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(OdbcType.Char, "char", "char(1) NULL", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(OdbcType.UniqueIdentifier, "uniqueidentifier", "uniqueidentifier NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(OdbcType.UniqueIdentifier, "uniqueidentifier", "uniqueidentifier", false, true, null) },
             };
diff --git a/Providers/FreeSql.Provider.Oracle/OracleAdo/OracleAdo.cs b/Providers/FreeSql.Provider.Oracle/OracleAdo/OracleAdo.cs
index 59ac3c98..f0c42708 100644
--- a/Providers/FreeSql.Provider.Oracle/OracleAdo/OracleAdo.cs
+++ b/Providers/FreeSql.Provider.Oracle/OracleAdo/OracleAdo.cs
@@ -42,8 +42,10 @@ namespace FreeSql.Oracle
                 return $"hextoraw('{CommonUtils.BytesSqlRaw(param as byte[])}')";
             else if (param is bool || param is bool?)
                 return (bool)param ? 1 : 0;
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Oracle/OracleCodeFirst.cs b/Providers/FreeSql.Provider.Oracle/OracleCodeFirst.cs
index 6bb3411a..7cdeeeb0 100644
--- a/Providers/FreeSql.Provider.Oracle/OracleCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Oracle/OracleCodeFirst.cs
@@ -44,6 +44,7 @@ namespace FreeSql.Oracle
 
                 { typeof(byte[]).FullName, CsToDb.New(OracleDbType.Blob, "blob", "blob NULL", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(OracleDbType.NVarchar2, "nvarchar2", "nvarchar2(255) NULL", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(OracleDbType.Char, "char", "char(1 CHAR) NULL", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(OracleDbType.Char, "char", "char(36 CHAR) NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(OracleDbType.Char, "char", "char(36 CHAR) NULL", false, true, null) },
             };
diff --git a/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLAdo/PostgreSQLAdo.cs b/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLAdo/PostgreSQLAdo.cs
index 3e9423dc..12bfafcc 100644
--- a/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLAdo/PostgreSQLAdo.cs
+++ b/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLAdo/PostgreSQLAdo.cs
@@ -44,8 +44,10 @@ namespace FreeSql.PostgreSQL
             bool isdic;
             if (param is bool || param is bool?)
                 return (bool)param ? "'t'" : "'f'";
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLCodeFirst.cs b/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLCodeFirst.cs
index c7834ba8..c0bc4d02 100644
--- a/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLCodeFirst.cs
+++ b/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLCodeFirst.cs
@@ -39,6 +39,7 @@ namespace FreeSql.PostgreSQL
                 { typeof(decimal).FullName, CsToDb.New(NpgsqlDbType.Numeric, "numeric", "numeric(10,2) NOT NULL", false, false, 0) },{ typeof(decimal?).FullName, CsToDb.New(NpgsqlDbType.Numeric, "numeric", "numeric(10,2)", false, true, null) },
 
                 { typeof(string).FullName, CsToDb.New(NpgsqlDbType.Varchar, "varchar", "varchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(NpgsqlDbType.Char, "bpchar", "bpchar(1)", false, null, '\0') },
 
                 { typeof(TimeSpan).FullName, CsToDb.New(NpgsqlDbType.Time, "time","time NOT NULL", false, false, 0) },{ typeof(TimeSpan?).FullName, CsToDb.New(NpgsqlDbType.Time, "time", "time",false, true, null) },
                 { typeof(DateTime).FullName, CsToDb.New(NpgsqlDbType.Timestamp, "timestamp", "timestamp NOT NULL", false, false, new DateTime(1970,1,1)) },{ typeof(DateTime?).FullName, CsToDb.New(NpgsqlDbType.Timestamp, "timestamp", "timestamp", false, true, null) },
diff --git a/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLUtils.cs b/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLUtils.cs
index ed6cb447..30d9422c 100644
--- a/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLUtils.cs
+++ b/Providers/FreeSql.Provider.PostgreSQL/PostgreSQLUtils.cs
@@ -44,6 +44,7 @@ namespace FreeSql.PostgreSQL
             { typeof(ushort).FullName, a => int.Parse(string.Concat(a)) }, { typeof(ushort[]).FullName, a => getParamterArrayValue(typeof(int), a, 0) }, { typeof(ushort?[]).FullName, a => getParamterArrayValue(typeof(int?), a, null) },
             { typeof(byte).FullName, a => short.Parse(string.Concat(a)) }, { typeof(byte[]).FullName, a => getParamterArrayValue(typeof(short), a, 0) }, { typeof(byte?[]).FullName, a => getParamterArrayValue(typeof(short?), a, null) },
             { typeof(sbyte).FullName, a => short.Parse(string.Concat(a)) }, { typeof(sbyte[]).FullName, a => getParamterArrayValue(typeof(short), a, 0) }, { typeof(sbyte?[]).FullName, a => getParamterArrayValue(typeof(short?), a, null) },
+            { typeof(char).FullName, a => string.Concat(a).Replace('\0', ' ').ToCharArray().FirstOrDefault() }, 
 
             { typeof(NpgsqlPath).FullName, a => {
                 var path = (NpgsqlPath)a;
@@ -70,6 +71,7 @@ namespace FreeSql.PostgreSQL
         static object getParamterValue(Type type, object value, int level = 0)
         {
             if (type.FullName == "System.Byte[]") return value;
+            if (type.FullName == "System.Char[]") return value;
             if (type.IsArray && level == 0)
             {
                 var elementType = type.GetElementType();
diff --git a/Providers/FreeSql.Provider.ShenTong/ShenTongAdo/ShenTongAdo.cs b/Providers/FreeSql.Provider.ShenTong/ShenTongAdo/ShenTongAdo.cs
index fee92115..eaa0e7b3 100644
--- a/Providers/FreeSql.Provider.ShenTong/ShenTongAdo/ShenTongAdo.cs
+++ b/Providers/FreeSql.Provider.ShenTong/ShenTongAdo/ShenTongAdo.cs
@@ -42,8 +42,10 @@ namespace FreeSql.ShenTong
 
             if (param is bool || param is bool?)
                 return (bool)param ? "'t'" : "'f'";
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.ShenTong/ShenTongCodeFirst.cs b/Providers/FreeSql.Provider.ShenTong/ShenTongCodeFirst.cs
index efe5d19e..2b369a01 100644
--- a/Providers/FreeSql.Provider.ShenTong/ShenTongCodeFirst.cs
+++ b/Providers/FreeSql.Provider.ShenTong/ShenTongCodeFirst.cs
@@ -37,6 +37,7 @@ namespace FreeSql.ShenTong
                 { typeof(decimal).FullName, CsToDb.New(OscarDbType.Numeric, "numeric", "numeric(10,2) NOT NULL", false, false, 0) },{ typeof(decimal?).FullName, CsToDb.New(OscarDbType.Numeric, "numeric", "numeric(10,2)", false, true, null) },
 
                 { typeof(string).FullName, CsToDb.New(OscarDbType.VarChar, "varchar", "varchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(OscarDbType.Char, "bpchar", "bpchar(1)", false, null, '\0') },
 
                 { typeof(TimeSpan).FullName, CsToDb.New(OscarDbType.Time, "time","time NOT NULL", false, false, 0) },{ typeof(TimeSpan?).FullName, CsToDb.New(OscarDbType.Time, "time", "time",false, true, null) },
                 { typeof(DateTime).FullName, CsToDb.New(OscarDbType.TimeStamp, "timestamp", "timestamp NOT NULL", false, false, new DateTime(1970,1,1)) },{ typeof(DateTime?).FullName, CsToDb.New(OscarDbType.TimeStamp, "timestamp", "timestamp", false, true, null) },
@@ -242,7 +243,7 @@ where ns.nspname = {0} and c.relname = {1}", tboldname ?? tbname);
                             var isCommentChanged = tbstructcol.comment != (tbcol.Comment ?? "");
                             if (tbcol.Attribute.DbType.StartsWith(tbstructcol.sqlType, StringComparison.CurrentCultureIgnoreCase) == false ||
                                 tbcol.Attribute.DbType.Contains("[]") != (tbstructcol.attndims > 0))
-                                sbalter.Append("ALTER TABLE ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" ALTER COLUMN ").Append(_commonUtils.QuoteSqlName(tbstructcol.column)).Append(" TYPE ").Append(tbcol.Attribute.DbType.Split(' ').First()).Append(";\r\n");
+                                sbalter.Append("ALTER TABLE ").Append(_commonUtils.QuoteSqlName($"{tbname[0]}.{tbname[1]}")).Append(" ALTER TYPE ").Append(_commonUtils.QuoteSqlName(tbstructcol.column)).Append(" ").Append(tbcol.Attribute.DbType.Split(' ').First()).Append(";\r\n");
                             if (tbcol.Attribute.IsNullable != tbstructcol.is_nullable)
                             {
                                 if (tbcol.Attribute.IsNullable != true || tbcol.Attribute.IsNullable == true && tbcol.Attribute.IsPrimary == false)
diff --git a/Providers/FreeSql.Provider.ShenTong/ShenTongUtils.cs b/Providers/FreeSql.Provider.ShenTong/ShenTongUtils.cs
index 227d7c13..bf0e67f4 100644
--- a/Providers/FreeSql.Provider.ShenTong/ShenTongUtils.cs
+++ b/Providers/FreeSql.Provider.ShenTong/ShenTongUtils.cs
@@ -38,6 +38,7 @@ namespace FreeSql.ShenTong
             { typeof(ushort).FullName, a => int.Parse(string.Concat(a)) }, { typeof(ushort[]).FullName, a => getParamterArrayValue(typeof(int), a, 0) }, { typeof(ushort?[]).FullName, a => getParamterArrayValue(typeof(int?), a, null) },
             { typeof(byte).FullName, a => short.Parse(string.Concat(a)) }, { typeof(byte[]).FullName, a => getParamterArrayValue(typeof(short), a, 0) }, { typeof(byte?[]).FullName, a => getParamterArrayValue(typeof(short?), a, null) },
             { typeof(sbyte).FullName, a => short.Parse(string.Concat(a)) }, { typeof(sbyte[]).FullName, a => getParamterArrayValue(typeof(short), a, 0) }, { typeof(sbyte?[]).FullName, a => getParamterArrayValue(typeof(short?), a, null) },
+            { typeof(char).FullName, a => string.Concat(a).Replace('\0', ' ').ToCharArray().FirstOrDefault() },
         };
         static object getParamterValue(Type type, object value, int level = 0)
         {
diff --git a/Providers/FreeSql.Provider.SqlServer/SqlServerAdo/SqlServerAdo.cs b/Providers/FreeSql.Provider.SqlServer/SqlServerAdo/SqlServerAdo.cs
index ea278f04..577eb94a 100644
--- a/Providers/FreeSql.Provider.SqlServer/SqlServerAdo/SqlServerAdo.cs
+++ b/Providers/FreeSql.Provider.SqlServer/SqlServerAdo/SqlServerAdo.cs
@@ -51,7 +51,7 @@ namespace FreeSql.SqlServer
                 return string.Concat("N'", param.ToString().Replace("'", "''"), "'");
             }
             else if (param is char)
-                return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.SqlServer/SqlServerCodeFirst.cs b/Providers/FreeSql.Provider.SqlServer/SqlServerCodeFirst.cs
index a62f4e24..450555ff 100644
--- a/Providers/FreeSql.Provider.SqlServer/SqlServerCodeFirst.cs
+++ b/Providers/FreeSql.Provider.SqlServer/SqlServerCodeFirst.cs
@@ -40,6 +40,7 @@ namespace FreeSql.SqlServer
 
                 { typeof(byte[]).FullName, CsToDb.New(SqlDbType.VarBinary, "varbinary", "varbinary(255)", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(SqlDbType.NVarChar, "nvarchar", "nvarchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(SqlDbType.Char, "char", "char(1)", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(SqlDbType.UniqueIdentifier, "uniqueidentifier", "uniqueidentifier NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(SqlDbType.UniqueIdentifier, "uniqueidentifier", "uniqueidentifier", false, true, null) },
             };
diff --git a/Providers/FreeSql.Provider.Sqlite/SqliteAdo/SqliteAdo.cs b/Providers/FreeSql.Provider.Sqlite/SqliteAdo/SqliteAdo.cs
index c1cc9252..1f928e46 100644
--- a/Providers/FreeSql.Provider.Sqlite/SqliteAdo/SqliteAdo.cs
+++ b/Providers/FreeSql.Provider.Sqlite/SqliteAdo/SqliteAdo.cs
@@ -43,8 +43,10 @@ namespace FreeSql.Sqlite
 
             if (param is bool || param is bool?)
                 return (bool)param ? 1 : 0;
-            else if (param is string || param is char)
+            else if (param is string)
                 return string.Concat("'", param.ToString().Replace("'", "''"), "'");
+            else if (param is char)
+                return string.Concat("'", param.ToString().Replace("'", "''").Replace('\0', ' '), "'");
             else if (param is Enum)
                 return ((Enum)param).ToInt64();
             else if (decimal.TryParse(string.Concat(param), out var trydec))
diff --git a/Providers/FreeSql.Provider.Sqlite/SqliteCodeFirst.cs b/Providers/FreeSql.Provider.Sqlite/SqliteCodeFirst.cs
index 3d8dc14f..fee7a0b0 100644
--- a/Providers/FreeSql.Provider.Sqlite/SqliteCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Sqlite/SqliteCodeFirst.cs
@@ -38,6 +38,7 @@ namespace FreeSql.Sqlite
 
                 { typeof(byte[]).FullName, CsToDb.New(DbType.Binary, "blob", "blob", false, null, new byte[0]) },
                 { typeof(string).FullName, CsToDb.New(DbType.String, "nvarchar", "nvarchar(255)", false, null, "") },
+                { typeof(char).FullName, CsToDb.New(DbType.AnsiString, "char", "char(1)", false, null, '\0') },
 
                 { typeof(Guid).FullName, CsToDb.New(DbType.Guid, "character", "character(36) NOT NULL", false, false, Guid.Empty) },{ typeof(Guid?).FullName, CsToDb.New(DbType.Guid, "character", "character(36)", false, true, null) },
             };