src/Model.php
protected static function _in($col, array $arr) {
        $ret = $col.' IN (';
        if (empty($arr))
            return $ret . 'null)';
        foreach ($arr as $val)
            $ret .= $val.', ';
        return substr($ret, 0, strrpos($ret, ',')) . ')';
    }
protected static function _in($col, array $arr) {
        $ret = $col.' IN (';
        if (empty($arr))
            return $ret . 'null)';
        foreach ($arr as $val)
            $ret .= $val.', ';
        return substr($ret, 0, strrpos($ret, ',')) . ')';
    }
protected static function _in ( $ col , array $ arr ) { $ ret = $ col . ' IN (' ; if ( empty ( $ arr ) ) return $ ret . 'null)' ; foreach ( $ arr as $ val ) $ ret .= $ val . ', ' ; return substr ( $ ret , 0 , strrpos ( $ ret , ',' ) ) . ')' ; }
构造WHERE IN语句

@param $col
@param array $arr
@return string
构造WHERE IN语句