Update exp to sql

Src/Asp.NetCore2/SqlSugar/ExpressionsToSql/Subquery/Items/SubWhere.cs

@@ -89,7 +89,7 @@ namespace SqlSugar
             var selfParameterName = Context.GetTranslationColumnName((argExp as LambdaExpression).Parameters.First().Name) + UtilConstants.Dot;
             if (this.Context.JoinIndex == 0&&result.Contains(" FROM ")) 
             {
-                this.Context.CurrentShortName= selfParameterName;
+                this.Context.CurrentShortName= selfParameterName.ObjToString().TrimEnd('.');
             }
             else if (this.Context.JoinIndex == 0)
                 result = result.Replace(selfParameterName, SubTools.GetSubReplace(this.Context));