/**
     * [array_to_sql 根据数组key和value拼接成需要的sql]
     * @param  [type] $array   [key, value结构数组]
     * @param  string $type    [sql类型insert,update]
     * @param  array  $exclude [排除的字段]
     * @return [string]          [返回拼接好的sql]
     */
    function array_to_sql($array, $type='insert', $exclude = array()){
        
        $sql = '';
        if(count($array) > 0){
            foreach ($exclude as $exkey) {
                unset($array[$exkey]);//剔除不要的key
            }

            if('insert' == $type){
                $keys = array_keys($array);
                $values = array_values($array);
                $col = implode("`, `", $keys);
                $val = implode("', '", $values);
                $sql = "(`$col`) values('$val')";
            }else if('update' == $type){
                $tempsql = '';
                $temparr = array();
                foreach ($array as $key => $value) {
                    $tempsql = "'$key' = '$value'";
                    $temparr[] = $tempsql;
                }

                $sql = implode(",", $temparr);
            }
        }
        return $sql;
    }