Update MySql

Src/Asp.Net/MySqlTest/Demos/5_CodeFirst.cs

@@ -13,7 +13,7 @@ namespace OrmTest.Demo
         public int Id { get; set; }
         [SugarColumn(Length = 21,OldColumnName = "Name2")]
         public string Name{ get; set; }
-        [SugarColumn(IsNullable = true,Length =10)]
+        [SugarColumn(IsNullable = true,Length =11)]
         public string IsOk { get; set; }
         public Guid Guid { get; set; }
         public decimal Decimal { get; set; }

Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs

@@ -163,13 +163,7 @@ namespace SqlSugar
                     }
                     else if (pkDiff || idEntityDiff)
                     {
-                        string constraintName = string.Format("PK_{0}_{1}", tableName, item.DbColumnName);
-                        if (this.Context.DbMaintenance.IsAnyConstraint(constraintName))
-                            this.Context.DbMaintenance.DropConstraint(tableName, constraintName);
-                        this.Context.DbMaintenance.DropColumn(tableName, item.DbColumnName);
-                        this.Context.DbMaintenance.AddColumn(tableName, EntityColumnToDbColumn(entityInfo, tableName, item));
-                        if (item.IsPrimarykey)
-                            this.Context.DbMaintenance.AddPrimaryKey(tableName, item.DbColumnName);
+                        ChangeKey(entityInfo, tableName, item);
                     }
                 }
                 if (isChange && IsBackupTable)
@@ -179,6 +173,17 @@ namespace SqlSugar
             }
         }
 
+        protected virtual void ChangeKey(EntityInfo entityInfo, string tableName, EntityColumnInfo item)
+        {
+            string constraintName = string.Format("PK_{0}_{1}", tableName, item.DbColumnName);
+            if (this.Context.DbMaintenance.IsAnyConstraint(constraintName))
+                this.Context.DbMaintenance.DropConstraint(tableName, constraintName);
+            this.Context.DbMaintenance.DropColumn(tableName, item.DbColumnName);
+            this.Context.DbMaintenance.AddColumn(tableName, EntityColumnToDbColumn(entityInfo, tableName, item));
+            if (item.IsPrimarykey)
+                this.Context.DbMaintenance.AddPrimaryKey(tableName, item.DbColumnName);
+        }
+
         protected virtual void ConvertColumns(List<DbColumnInfo> dbColumns)
         {
            

Src/Asp.Net/SqlSugar/Realization/MySql/CodeFirst/MySqlCodeFirst.cs

@@ -5,7 +5,7 @@ using System.Text;
 
 namespace SqlSugar
 {
-    public class MySqlCodeFirst:CodeFirstProvider
+    public class MySqlCodeFirst : CodeFirstProvider
     {
         public override void NoExistLogic(EntityInfo entityInfo)
         {
@@ -37,7 +37,8 @@ namespace SqlSugar
                 ColumnDescription = item.ColumnDescription,
                 Length = item.Length
             };
-            if (result.DataType.Equals("varchar",StringComparison.CurrentCultureIgnoreCase)&& result.Length == 0) {
+            if (result.DataType.Equals("varchar", StringComparison.CurrentCultureIgnoreCase) && result.Length == 0)
+            {
                 result.Length = 1;
             }
             return result;
@@ -47,10 +48,20 @@ namespace SqlSugar
         {
             foreach (var item in dbColumns)
             {
-                if (item.DataType == "DateTime") {
+                if (item.DataType == "DateTime")
+                {
                     item.Length = 0;
                 }
             }
         }
+
+        protected override void ChangeKey(EntityInfo entityInfo, string tableName, EntityColumnInfo item)
+        {
+            this.Context.DbMaintenance.UpdateColumn(tableName, EntityColumnToDbColumn(entityInfo, tableName, item));
+            if (!item.IsPrimarykey)
+                this.Context.DbMaintenance.DropConstraint(tableName,null);
+            if (item.IsPrimarykey)
+                this.Context.DbMaintenance.AddPrimaryKey(tableName, item.DbColumnName);
+        }
     }
 }

Src/Asp.Net/SqlSugar/Realization/MySql/DbMaintenance/MySqlDbMaintenance.cs

@@ -104,7 +104,7 @@ namespace SqlSugar
         {
             get
             {
-                return "SELECT TOP {0} *　INTO {1} FROM  {2}";
+                return "SELECT  *　INTO {1} FROM  {2} limit 0,{0}";
             }
         }
         protected override string DropTableSql
@@ -125,7 +125,7 @@ namespace SqlSugar
         {
             get
             {
-                return "ALTER TABLE {0} DROP CONSTRAINT  {1}";
+                return "ALTER TABLE {0} drop primary key;";
             }
         }
         protected override string RenameColumnSql