diff --git a/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/Curd/MySqlUpdateTest.cs b/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/Curd/MySqlUpdateTest.cs
index 1a2242ab..050e8e22 100644
--- a/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/Curd/MySqlUpdateTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests.Provider.MySqlConnector/MySqlConnector/Curd/MySqlUpdateTest.cs
@@ -46,6 +46,7 @@ namespace FreeSql.Tests.MySqlConnector
 
             var items = new List<Topic>();
             for (var a = 0; a < 10; a++) items.Add(new Topic { Id = a + 1, Title = $"newtitle{a}", Clicks = a * 100 });
+            items[0].Clicks = null;
 
             sql = update.SetSource(items).ToSql().Replace("\r\n", "");
             Assert.Equal("UPDATE `tb_topic` SET `Clicks` = CASE `Id` WHEN 1 THEN @p_0 WHEN 2 THEN @p_1 WHEN 3 THEN @p_2 WHEN 4 THEN @p_3 WHEN 5 THEN @p_4 WHEN 6 THEN @p_5 WHEN 7 THEN @p_6 WHEN 8 THEN @p_7 WHEN 9 THEN @p_8 WHEN 10 THEN @p_9 END, `Title` = CASE `Id` WHEN 1 THEN @p_10 WHEN 2 THEN @p_11 WHEN 3 THEN @p_12 WHEN 4 THEN @p_13 WHEN 5 THEN @p_14 WHEN 6 THEN @p_15 WHEN 7 THEN @p_16 WHEN 8 THEN @p_17 WHEN 9 THEN @p_18 WHEN 10 THEN @p_19 END, `CreateTime` = CASE `Id` WHEN 1 THEN @p_20 WHEN 2 THEN @p_21 WHEN 3 THEN @p_22 WHEN 4 THEN @p_23 WHEN 5 THEN @p_24 WHEN 6 THEN @p_25 WHEN 7 THEN @p_26 WHEN 8 THEN @p_27 WHEN 9 THEN @p_28 WHEN 10 THEN @p_29 END WHERE (`Id` IN (1,2,3,4,5,6,7,8,9,10))", sql);
diff --git a/FreeSql.Tests/FreeSql.Tests/MySql/Curd/MySqlUpdateTest.cs b/FreeSql.Tests/FreeSql.Tests/MySql/Curd/MySqlUpdateTest.cs
index 381df6fa..7d42b257 100644
--- a/FreeSql.Tests/FreeSql.Tests/MySql/Curd/MySqlUpdateTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/MySql/Curd/MySqlUpdateTest.cs
@@ -47,6 +47,7 @@ namespace FreeSql.Tests.MySql
 
             var items = new List<Topic>();
             for (var a = 0; a < 10; a++) items.Add(new Topic { Id = a + 1, Title = $"newtitle{a}", Clicks = a * 100 });
+            items[0].Clicks = null;
 
             sql = update.SetSource(items).ToSql().Replace("\r\n", "");
             Assert.Equal("UPDATE `tb_topic` SET `Clicks` = CASE `Id` WHEN 1 THEN ?p_0 WHEN 2 THEN ?p_1 WHEN 3 THEN ?p_2 WHEN 4 THEN ?p_3 WHEN 5 THEN ?p_4 WHEN 6 THEN ?p_5 WHEN 7 THEN ?p_6 WHEN 8 THEN ?p_7 WHEN 9 THEN ?p_8 WHEN 10 THEN ?p_9 END, `Title` = CASE `Id` WHEN 1 THEN ?p_10 WHEN 2 THEN ?p_11 WHEN 3 THEN ?p_12 WHEN 4 THEN ?p_13 WHEN 5 THEN ?p_14 WHEN 6 THEN ?p_15 WHEN 7 THEN ?p_16 WHEN 8 THEN ?p_17 WHEN 9 THEN ?p_18 WHEN 10 THEN ?p_19 END, `CreateTime` = CASE `Id` WHEN 1 THEN ?p_20 WHEN 2 THEN ?p_21 WHEN 3 THEN ?p_22 WHEN 4 THEN ?p_23 WHEN 5 THEN ?p_24 WHEN 6 THEN ?p_25 WHEN 7 THEN ?p_26 WHEN 8 THEN ?p_27 WHEN 9 THEN ?p_28 WHEN 10 THEN ?p_29 END WHERE (`Id` IN (1,2,3,4,5,6,7,8,9,10))", sql);
diff --git a/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs b/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs
index 35f7e27d..a3017d2d 100644
--- a/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/MySql/MySqlCodeFirstTest.cs
@@ -218,6 +218,8 @@ namespace FreeSql.Tests.MySql
             var sqlText = insert.AppendData(item2).NoneParameter().ToSql();
             var item3NP = insert.AppendData(item2).NoneParameter().ExecuteIdentity();
 
+            var enumConvInt = select.Where(a => a.Id == (int)TableAllTypeEnumType1.e1).ToSql();
+
             item2.Id = (int)insert.AppendData(item2).ExecuteIdentity();
             var newitem2 = select.Where(a => a.Id == item2.Id).ToOne();
 
diff --git a/FreeSql.Tests/FreeSql.Tests/Oracle/Curd/OracleUpdateTest.cs b/FreeSql.Tests/FreeSql.Tests/Oracle/Curd/OracleUpdateTest.cs
index 11b061be..0f374c2b 100644
--- a/FreeSql.Tests/FreeSql.Tests/Oracle/Curd/OracleUpdateTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/Oracle/Curd/OracleUpdateTest.cs
@@ -38,6 +38,7 @@ namespace FreeSql.Tests.Oracle
 
             var items = new List<Topic>();
             for (var a = 0; a < 10; a++) items.Add(new Topic { Id = a + 1, Title = $"newtitle{a}", Clicks = a * 100 });
+            items[0].Clicks = null;
 
             sql = update.SetSource(items).ToSql().Replace("\r\n", "");
             Assert.Equal("UPDATE \"TB_TOPIC\" SET \"CLICKS\" = CASE \"ID\" WHEN 1 THEN :p_0 WHEN 2 THEN :p_1 WHEN 3 THEN :p_2 WHEN 4 THEN :p_3 WHEN 5 THEN :p_4 WHEN 6 THEN :p_5 WHEN 7 THEN :p_6 WHEN 8 THEN :p_7 WHEN 9 THEN :p_8 WHEN 10 THEN :p_9 END, \"TITLE\" = CASE \"ID\" WHEN 1 THEN :p_10 WHEN 2 THEN :p_11 WHEN 3 THEN :p_12 WHEN 4 THEN :p_13 WHEN 5 THEN :p_14 WHEN 6 THEN :p_15 WHEN 7 THEN :p_16 WHEN 8 THEN :p_17 WHEN 9 THEN :p_18 WHEN 10 THEN :p_19 END, \"CREATETIME\" = CASE \"ID\" WHEN 1 THEN :p_20 WHEN 2 THEN :p_21 WHEN 3 THEN :p_22 WHEN 4 THEN :p_23 WHEN 5 THEN :p_24 WHEN 6 THEN :p_25 WHEN 7 THEN :p_26 WHEN 8 THEN :p_27 WHEN 9 THEN :p_28 WHEN 10 THEN :p_29 END WHERE (\"ID\" IN (1,2,3,4,5,6,7,8,9,10))", sql);
diff --git a/FreeSql.Tests/FreeSql.Tests/PostgreSQL/Curd/PostgreSQLUpdateTest.cs b/FreeSql.Tests/FreeSql.Tests/PostgreSQL/Curd/PostgreSQLUpdateTest.cs
index ff270d94..7d7104d0 100644
--- a/FreeSql.Tests/FreeSql.Tests/PostgreSQL/Curd/PostgreSQLUpdateTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/PostgreSQL/Curd/PostgreSQLUpdateTest.cs
@@ -39,6 +39,7 @@ namespace FreeSql.Tests.PostgreSQL
 
             var items = new List<Topic>();
             for (var a = 0; a < 10; a++) items.Add(new Topic { Id = a + 1, Title = $"newtitle{a}", Clicks = a * 100 });
+            items[0].Clicks = null;
 
             sql = update.SetSource(items).ToSql().Replace("\r\n", "");
             Assert.Equal("UPDATE \"tb_topic\" SET \"clicks\" = CASE \"id\" WHEN 1 THEN @p_0 WHEN 2 THEN @p_1 WHEN 3 THEN @p_2 WHEN 4 THEN @p_3 WHEN 5 THEN @p_4 WHEN 6 THEN @p_5 WHEN 7 THEN @p_6 WHEN 8 THEN @p_7 WHEN 9 THEN @p_8 WHEN 10 THEN @p_9 END, \"title\" = CASE \"id\" WHEN 1 THEN @p_10 WHEN 2 THEN @p_11 WHEN 3 THEN @p_12 WHEN 4 THEN @p_13 WHEN 5 THEN @p_14 WHEN 6 THEN @p_15 WHEN 7 THEN @p_16 WHEN 8 THEN @p_17 WHEN 9 THEN @p_18 WHEN 10 THEN @p_19 END, \"createtime\" = CASE \"id\" WHEN 1 THEN @p_20 WHEN 2 THEN @p_21 WHEN 3 THEN @p_22 WHEN 4 THEN @p_23 WHEN 5 THEN @p_24 WHEN 6 THEN @p_25 WHEN 7 THEN @p_26 WHEN 8 THEN @p_27 WHEN 9 THEN @p_28 WHEN 10 THEN @p_29 END WHERE (\"id\" IN (1,2,3,4,5,6,7,8,9,10))", sql);
diff --git a/FreeSql.Tests/FreeSql.Tests/SqlServer/Curd/SqlServerUpdateTest.cs b/FreeSql.Tests/FreeSql.Tests/SqlServer/Curd/SqlServerUpdateTest.cs
index 88ad4cb0..2c2cfc31 100644
--- a/FreeSql.Tests/FreeSql.Tests/SqlServer/Curd/SqlServerUpdateTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/SqlServer/Curd/SqlServerUpdateTest.cs
@@ -50,6 +50,7 @@ namespace FreeSql.Tests.SqlServer
 
             var items = new List<Topic>();
             for (var a = 0; a < 10; a++) items.Add(new Topic { Id = a + 1, Title = $"newtitle{a}", Clicks = a * 100 });
+            items[0].Clicks = null;
 
             sql = update.SetSource(items).IgnoreColumns(a => a.TypeGuid).ToSql().Replace("\r\n", "");
             Assert.Equal("UPDATE [tb_topic] SET [Clicks] = CASE [Id] WHEN 1 THEN @p_0 WHEN 2 THEN @p_1 WHEN 3 THEN @p_2 WHEN 4 THEN @p_3 WHEN 5 THEN @p_4 WHEN 6 THEN @p_5 WHEN 7 THEN @p_6 WHEN 8 THEN @p_7 WHEN 9 THEN @p_8 WHEN 10 THEN @p_9 END, [Title] = CASE [Id] WHEN 1 THEN @p_10 WHEN 2 THEN @p_11 WHEN 3 THEN @p_12 WHEN 4 THEN @p_13 WHEN 5 THEN @p_14 WHEN 6 THEN @p_15 WHEN 7 THEN @p_16 WHEN 8 THEN @p_17 WHEN 9 THEN @p_18 WHEN 10 THEN @p_19 END, [CreateTime] = CASE [Id] WHEN 1 THEN @p_20 WHEN 2 THEN @p_21 WHEN 3 THEN @p_22 WHEN 4 THEN @p_23 WHEN 5 THEN @p_24 WHEN 6 THEN @p_25 WHEN 7 THEN @p_26 WHEN 8 THEN @p_27 WHEN 9 THEN @p_28 WHEN 10 THEN @p_29 END WHERE ([Id] IN (1,2,3,4,5,6,7,8,9,10))", sql);
diff --git a/FreeSql.Tests/FreeSql.Tests/Sqlite/Curd/SqliteUpdateTest.cs b/FreeSql.Tests/FreeSql.Tests/Sqlite/Curd/SqliteUpdateTest.cs
index e6c74398..136a4eb3 100644
--- a/FreeSql.Tests/FreeSql.Tests/Sqlite/Curd/SqliteUpdateTest.cs
+++ b/FreeSql.Tests/FreeSql.Tests/Sqlite/Curd/SqliteUpdateTest.cs
@@ -40,6 +40,7 @@ namespace FreeSql.Tests.Sqlite
 
             var items = new List<Topic>();
             for (var a = 0; a < 10; a++) items.Add(new Topic { Id = a + 1, Title = $"newtitle{a}", Clicks = a * 100 });
+            items[0].Clicks = null;
 
             sql = update.SetSource(items).IgnoreColumns(a => a.TypeGuid).ToSql().Replace("\r\n", "");
             Assert.Equal("UPDATE \"tb_topic\" SET \"Clicks\" = CASE \"Id\" WHEN 1 THEN @p_0 WHEN 2 THEN @p_1 WHEN 3 THEN @p_2 WHEN 4 THEN @p_3 WHEN 5 THEN @p_4 WHEN 6 THEN @p_5 WHEN 7 THEN @p_6 WHEN 8 THEN @p_7 WHEN 9 THEN @p_8 WHEN 10 THEN @p_9 END, \"Title\" = CASE \"Id\" WHEN 1 THEN @p_10 WHEN 2 THEN @p_11 WHEN 3 THEN @p_12 WHEN 4 THEN @p_13 WHEN 5 THEN @p_14 WHEN 6 THEN @p_15 WHEN 7 THEN @p_16 WHEN 8 THEN @p_17 WHEN 9 THEN @p_18 WHEN 10 THEN @p_19 END, \"CreateTime\" = CASE \"Id\" WHEN 1 THEN @p_20 WHEN 2 THEN @p_21 WHEN 3 THEN @p_22 WHEN 4 THEN @p_23 WHEN 5 THEN @p_24 WHEN 6 THEN @p_25 WHEN 7 THEN @p_26 WHEN 8 THEN @p_27 WHEN 9 THEN @p_28 WHEN 10 THEN @p_29 END WHERE (\"Id\" IN (1,2,3,4,5,6,7,8,9,10))", sql);
diff --git a/FreeSql/Internal/CommonProvider/UpdateProvider.cs b/FreeSql/Internal/CommonProvider/UpdateProvider.cs
index ce358480..de0e6930 100644
--- a/FreeSql/Internal/CommonProvider/UpdateProvider.cs
+++ b/FreeSql/Internal/CommonProvider/UpdateProvider.cs
@@ -576,7 +576,7 @@ namespace FreeSql.Internal.CommonProvider
                 var sb = new StringBuilder();
                 sb.Append(_commonUtils.QuoteSqlName(col.Attribute.Name)).Append(" = ");
 
-                var isnull = false;
+                var nulls = 0;
                 var cwsb = new StringBuilder().Append(cw);
                 foreach (var d in _source)
                 {
@@ -585,11 +585,11 @@ namespace FreeSql.Internal.CommonProvider
                     cwsb.Append(" THEN ");
                     var value = col.GetMapValue(d);
                     cwsb.Append(thenValue(_commonUtils.GetNoneParamaterSqlValue(_paramsSource, col.Attribute.MapType, value)));
-                    if (isnull == false) isnull = value == null || value == DBNull.Value;
+                    if (value == null || value == DBNull.Value) nulls++;
                 }
                 cwsb.Append(" END");
-                if (isnull == false) sb.Append(cwsb.ToString());
-                else sb.Append("NULL");
+                if (nulls == _source.Count) sb.Append("NULL");
+                else sb.Append(cwsb.ToString());
                 cwsb.Clear();
 
                 return sb.ToString();
@@ -669,7 +669,7 @@ namespace FreeSql.Internal.CommonProvider
                         if (colidx > 0) sb.Append(", ");
                         sb.Append(_commonUtils.QuoteSqlName(col.Attribute.Name)).Append(" = ");
 
-                        var isnull = false;
+                        var nulls = 0;
                         var cwsb = new StringBuilder().Append(cw);
                         foreach (var d in _source)
                         {
@@ -684,15 +684,15 @@ namespace FreeSql.Internal.CommonProvider
                                 cwsb.Append(_commonUtils.QuoteWriteParamter(col.Attribute.MapType, _commonUtils.QuoteParamterName($"p_{_paramsSource.Count}")));
                                 _commonUtils.AppendParamter(_paramsSource, null, col.Attribute.MapType, val);
                             }
-                            if (isnull == false) isnull = val == null || val == DBNull.Value;
+                            if (val == null || val == DBNull.Value) nulls++;
                         }
                         cwsb.Append(" END");
-                        if (isnull == false)
+                        if (nulls == _source.Count) sb.Append("NULL");
+                        else
                         {
                             ToSqlCaseWhenEnd(cwsb, col);
                             sb.Append(cwsb.ToString());
                         }
-                        else sb.Append("NULL");
                         cwsb.Clear();
 
                         ++colidx;