diff --git a/FreeSql.DbContext/FreeSql.DbContext.xml b/FreeSql.DbContext/FreeSql.DbContext.xml
index d8bba58b..28fdb213 100644
--- a/FreeSql.DbContext/FreeSql.DbContext.xml
+++ b/FreeSql.DbContext/FreeSql.DbContext.xml
@@ -110,13 +110,6 @@
             清空状态数据
             </summary>
         </member>
-        <member name="M:FreeSql.DbSet`1.RemoveAsync(System.Linq.Expressions.Expression{System.Func{`0,System.Boolean}})">
-            <summary>
-            根据 lambda 条件删除数据
-            </summary>
-            <param name="predicate"></param>
-            <returns></returns>
-        </member>
         <member name="M:FreeSql.DbSet`1.Add(`0)">
             <summary>
             添加
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/MySqlCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/MySqlCodeFirstTest.cs
index 86460dce..329b4e61 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/MySqlCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/MySqlCodeFirstTest.cs
@@ -10,6 +10,19 @@ namespace FreeSql.Tests.MySqlConnector
 {
     public class MySqlCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.mysql.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.mysql.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
+
         [Fact]
         public void �������е�()
         {
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Dameng/DamengCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Dameng/DamengCodeFirstTest.cs
index b5ba4461..44718c65 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Dameng/DamengCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Dameng/DamengCodeFirstTest.cs
@@ -10,6 +10,18 @@ namespace FreeSql.Tests.Odbc.Dameng
 {
     public class DamengCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.dameng.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.dameng.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
 
         [Fact]
         public void ���ı�_�ֶ�()
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Default/OdbcCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Default/OdbcCodeFirstTest.cs
index e04d5d40..1859e308 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Default/OdbcCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Default/OdbcCodeFirstTest.cs
@@ -11,6 +11,7 @@ namespace FreeSql.Tests.Odbc.Default
 
     public class OdbcCodeFirstTest
     {
+
         [Fact]
         public void 中文表_字段()
         {
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/MySql/MySqlCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/MySql/MySqlCodeFirstTest.cs
index 6c52d3ae..d0657318 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/MySql/MySqlCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/MySql/MySqlCodeFirstTest.cs
@@ -10,6 +10,19 @@ namespace FreeSql.Tests.Odbc.MySql
 {
     public class MySqlCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.mysql.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.mysql.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
+
         [Fact]
         public void �������е�()
         {
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Oracle/OracleCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Oracle/OracleCodeFirstTest.cs
index 2ae10e27..37482571 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Oracle/OracleCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/Oracle/OracleCodeFirstTest.cs
@@ -10,6 +10,18 @@ namespace FreeSql.Tests.Odbc.Oracle
 {
     public class OracleCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.oracle.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.oracle.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
 
         [Fact]
         public void ���ı�_�ֶ�()
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/PostgreSQL/PostgreSQLCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/PostgreSQL/PostgreSQLCodeFirstTest.cs
index 96a926fd..320146c0 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/PostgreSQL/PostgreSQLCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/PostgreSQL/PostgreSQLCodeFirstTest.cs
@@ -14,6 +14,18 @@ namespace FreeSql.Tests.Odbc.PostgreSQL
 {
     public class PostgreSQLCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.pgsql.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.pgsql.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
 
         [Fact]
         public void ���ı�_�ֶ�()
diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/SqlServer/SqlServerCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/SqlServer/SqlServerCodeFirstTest.cs
index 355854b2..ef642d6b 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/SqlServer/SqlServerCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.Odbc/SqlServer/SqlServerCodeFirstTest.cs
@@ -12,6 +12,19 @@ namespace FreeSql.Tests.Odbc.SqlServer
     [Collection("SqlServerCollection")]
     public class SqlServerCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.sqlserver.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.sqlserver.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
+
         [Fact]
         public void ���ı�_�ֶ�()
         {
diff --git a/FreeSql.Tests/FreeSql.Tests/MsAccess/MsAccessCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/MsAccess/MsAccessCodeFirstTest.cs
index bd27dc0c..ceeca39b 100644
--- a/FreeSql.Tests/FreeSql.Tests/MsAccess/MsAccessCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/MsAccess/MsAccessCodeFirstTest.cs
@@ -10,6 +10,18 @@ namespace FreeSql.Tests.MsAccess
 {
     public class MsAccessCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.msaccess.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.msaccess.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
 
         [Fact]
         public void ���ı�_�ֶ�()
diff --git a/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs
index ad7efc27..1c3cd9ed 100644
--- a/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs
@@ -10,6 +10,18 @@ namespace FreeSql.Tests.MySql
 {
     public class MySqlCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.mysql.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.mysql.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
 
         [Fact]
         public void �������е�()
diff --git a/FreeSql.Tests/FreeSql.Tests/Oracle/OracleCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/Oracle/OracleCodeFirstTest.cs
index f1eeab72..959a9b96 100644
--- a/FreeSql.Tests/FreeSql.Tests/Oracle/OracleCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/Oracle/OracleCodeFirstTest.cs
@@ -10,6 +10,18 @@ namespace FreeSql.Tests.Oracle
 {
     public class OracleCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.oracle.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.oracle.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
 
         [Fact]
         public void ���ı�_�ֶ�()
diff --git a/FreeSql.Tests/FreeSql.Tests/PostgreSQL/PostgreSQLCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/PostgreSQL/PostgreSQLCodeFirstTest.cs
index 75cd98d8..f131c212 100644
--- a/FreeSql.Tests/FreeSql.Tests/PostgreSQL/PostgreSQLCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/PostgreSQL/PostgreSQLCodeFirstTest.cs
@@ -17,6 +17,18 @@ namespace FreeSql.Tests.PostgreSQL
 {
     public class PostgreSQLCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.pgsql.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.pgsql.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
 
         [Fact]
         public void ���ı�_�ֶ�()
diff --git a/FreeSql.Tests/FreeSql.Tests/SqlServer/SqlServerCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/SqlServer/SqlServerCodeFirstTest.cs
index b86c0e2f..f3e55e01 100644
--- a/FreeSql.Tests/FreeSql.Tests/SqlServer/SqlServerCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/SqlServer/SqlServerCodeFirstTest.cs
@@ -11,6 +11,18 @@ namespace FreeSql.Tests.SqlServer
 {
     public class SqlServerCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.sqlserver.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.sqlserver.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
 
         [Fact]
         public void ���ı�_�ֶ�()
diff --git a/FreeSql.Tests/FreeSql.Tests/Sqlite/SqliteCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/Sqlite/SqliteCodeFirstTest.cs
index 1d48cb21..12073a43 100644
--- a/FreeSql.Tests/FreeSql.Tests/Sqlite/SqliteCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/Sqlite/SqliteCodeFirstTest.cs
@@ -10,6 +10,18 @@ namespace FreeSql.Tests.Sqlite
 {
     public class SqliteCodeFirstTest
     {
+        [Fact]
+        public void StringLength()
+        {
+            var dll = g.sqlite.CodeFirst.GetComparisonDDLStatements<TS_SLTB>();
+            g.sqlite.CodeFirst.SyncStructure<TS_SLTB>();
+        }
+        class TS_SLTB
+        {
+            public Guid Id { get; set; }
+            [Column(StringLength = 50)]
+            public string Title { get; set; }
+        }
 
         [Fact]
         public void �������е�()
diff --git a/FreeSql/Internal/UtilsExpressionTree.cs b/FreeSql/Internal/UtilsExpressionTree.cs
index d9dc1840..ffb1dfb8 100644
--- a/FreeSql/Internal/UtilsExpressionTree.cs
+++ b/FreeSql/Internal/UtilsExpressionTree.cs
@@ -204,7 +204,7 @@ namespace FreeSql.Internal
                 if (colattr.MapType == typeof(string) && colattr.StringLength != 0)
                 {
                     int strlen = colattr.StringLength;
-                    var charPatten = @"(CHAR|CHAR2|CHARACTER)\s*(\([^\)]*\))?";
+                    var charPatten = @"(CHARACTER|CHAR2|CHAR)\s*(\([^\)]*\))?";
                     switch (common._orm.Ado.DataType)
                     {
                         case DataType.MySql: