Update join

Src/Asp.NetCore2/MySqlTest/Demo/Demo2_Updateable.cs

@@ -66,8 +66,11 @@ namespace OrmTest
             var result8 = db.Updateable<Order>(it => it.Name == "Name" + "1").Where(it => it.Id == 1).ExecuteCommand();
             var result81 = db.Updateable<Order>().SetColumns(it => it.Name == "Name" + "1").Where(it => it.Id == 1).ExecuteCommand();
             //
-
-
+            var result61 = db.Updateable<Order>()
+            .InnerJoin<Custom>((x, y) => x.CustomId == y.Id)
+            .SetColumns((x, y) => new Order() { Name = y.Name, Price = y.Id })
+            .Where((x, y) => x.Id == 1)
+            .ExecuteCommand(); 
 
 
             /*** 3.by Dictionary ***/

Src/Asp.NetCore2/SqlSeverTest/Demo/Demo2_Updateable.cs

@@ -66,9 +66,11 @@ namespace OrmTest
             var result8 = db.Updateable<Order>(it => it.Name == "Name" + "1").Where(it => it.Id == 1).ExecuteCommand();
             var result81 = db.Updateable<Order>().SetColumns(it => it.Name == "Name" + "1").Where(it => it.Id == 1).ExecuteCommand();
             //
-
-
-
+            var result61 = db.Updateable<Order>()
+             .InnerJoin<Custom>((x, y) => x.CustomId == y.Id)
+             .SetColumns((x, y) => new Order() { Name = y.Name, Price=y.Id })
+             .Where((x, y) => x.Id == 1)
+             .ExecuteCommand();
 
             /*** 3.by Dictionary ***/
             var dt = new Dictionary<string, object>();

Src/Asp.NetCore2/SqlSugar/Abstract/UpdateProvider/UpdateableProviderT2.cs

@@ -36,7 +36,7 @@ namespace SqlSugar
             foreach (var item in items)
             {
                 var dbColumnName=updateableObj.UpdateBuilder.Context.EntityMaintenance.GetDbColumnName<T>(item.Key);
-                var value = updateableObj.UpdateBuilder.GetExpressionValue(item.Value, ResolveExpressType.WhereMultiple).GetString();
+                var value = updateableObj.UpdateBuilder.GetExpressionValue(ExpressionTool.RemoveConvert(item.Value), ResolveExpressType.WhereMultiple).GetString();
                 this.updateableObj.UpdateBuilder.SetValues.Add(new KeyValuePair<string, string>(dbColumnName, value));
             }
             UpdateBuilder.DbColumnInfoList = UpdateBuilder.DbColumnInfoList