public override SqlProvider FormatSum(LambdaExpression sumExpression) { var selectSql = ResolveExpression.ResolveSum(sumExpression); var fromTableSql = FormatTableName(); var whereSql = ResolveExpression.ResolveWhereList(); string noneSql = ""; var joinSql = ResolveExpression.ResolveJoinSql(JoinList, ref noneSql); SqlString = $"{selectSql} {fromTableSql}{joinSql} {whereSql} "; return(this); }