diff --git a/Examples/base_entity/Program.cs b/Examples/base_entity/Program.cs
index 84b9f7da..74c169e0 100644
--- a/Examples/base_entity/Program.cs
+++ b/Examples/base_entity/Program.cs
@@ -406,6 +406,18 @@ namespace base_entity
 
             using (IFreeSql client = CreateInstance(@"Driver={Microsoft Access Driver (*.mdb)};DBQ=d:/accdb/2007.accdb", DataType.Odbc))
             {
+                client.Aop.AuditValue += (_, e) =>
+                {
+                    if (e.Object is Dictionary<string, object> dict)
+                    {
+                        foreach(var key in dict.Keys)
+                        {
+                            var val = dict[key];
+                            if (val == DBNull.Value) dict[key] = null;
+                        }
+                        e.ObjectAuditBreak = true;
+                    }
+                };
                 Dictionary<string, object> data = new Dictionary<string, object>();
                 data.Add("ExpNo", "RSP0950008");
                 data.Add("SPoint", "RSP0950004");
diff --git a/FreeSql.DbContext/FreeSql.DbContext.xml b/FreeSql.DbContext/FreeSql.DbContext.xml
index 26522f10..537315e2 100644
--- a/FreeSql.DbContext/FreeSql.DbContext.xml
+++ b/FreeSql.DbContext/FreeSql.DbContext.xml
@@ -800,14 +800,5 @@
             <param name="that"></param>
             <returns></returns>
         </member>
-        <member name="M:Microsoft.Extensions.DependencyInjection.FreeSqlRepositoryDependencyInjection.AddFreeRepository(Microsoft.Extensions.DependencyInjection.IServiceCollection,System.Action{FreeSql.FluentDataFilter},System.Reflection.Assembly[])">
-            <summary>
-            批量注入 Repository，可以参考代码自行调整
-            </summary>
-            <param name="services"></param>
-            <param name="globalDataFilter"></param>
-            <param name="assemblies"></param>
-            <returns></returns>
-        </member>
     </members>
 </doc>
diff --git a/Providers/FreeSql.Provider.Custom/MySql/CustomMySqlCodeFirst.cs b/Providers/FreeSql.Provider.Custom/MySql/CustomMySqlCodeFirst.cs
index 8cce49e2..bee6e372 100644
--- a/Providers/FreeSql.Provider.Custom/MySql/CustomMySqlCodeFirst.cs
+++ b/Providers/FreeSql.Provider.Custom/MySql/CustomMySqlCodeFirst.cs
@@ -200,7 +200,7 @@ where a.table_schema in ({0}) and a.table_name in ({1})", tboldname ?? tbname);
 
                     if (istmpatler == false)
                     {
-                        var existsPrimary = LocalExecuteScalar(tbname[0], _commonUtils.FormatSql(" select 1 from information_schema.key_column_usage where table_schema={0} and table_name={1} and constraint_name = 'PRIMARY' limit 1", tbname));
+                        var existsPrimary = LocalExecuteScalar(tbname[0], _commonUtils.FormatSql(" select 1 from information_schema.columns where table_schema={0} and table_name={1} and column_key = 'PRI' limit 1", tbname));
                         foreach (var tbcol in tb.ColumnsByPosition)
                         {
                             var isIdentityChanged = tbcol.Attribute.IsIdentity == true && tbcol.Attribute.DbType.IndexOf("AUTO_INCREMENT", StringComparison.CurrentCultureIgnoreCase) == -1;