src/NotORM/Result.php
function limit($limit, $offset = null){
        $this->rows = null;
        if($this->union){
            $this->unionLimit  = +$limit;
            $this->unionOffset = +$offset;
        }else{
            $this->limit  = +$limit;
            $this->offset = +$offset;
        }
        return $this;
    }
function limit($limit, $offset = null){
        $this->rows = null;
        if($this->union){
            $this->unionLimit  = +$limit;
            $this->unionOffset = +$offset;
        }else{
            $this->limit  = +$limit;
            $this->offset = +$offset;
        }
        return $this;
    }
对查询进行limit操作
请注意以下两种用法，与NotORM原来的定义有所区别
- limit(数量)
- limit(开始位置，数量)
Set limit clause, more calls rewrite old values

@param int
@param int

@return NotORM_Result fluent interface