如何优化查询逻辑?
看如下代码:
php
$bankroll = $this->sgoods_bankroll->order('sb_id desc')->limit(50)->select(); foreach ($bankroll as $k=>&$v) { $sl_id = $this->bankrollpop_relations->where(array('br_sb_id'=>$v['sb_id']))->getField('br_sl_id'); $v['dang_name'] = $this->settlementpop_list->where(array('sl_id'=>$sl_id))->getField('sl_schedule_name'); }
首先查询一个列表,然后foreach这个列表每条记录,再执行两次查询,一次去relations关联表找另一个表的关联字段,一次根据这个关联字段查询表另一个字段。
如果每次foreach查两次数据库的话,那整个下来不是查几百次数据库,这样是不是效率很低,一般这种情况可以怎么优化查询逻辑?
恢复正常了吗
9 years, 10 months ago
Answers
有个办法就是先foreach一遍得到所有的ids,去relations表一次查出关联的其他表的id,再根据这些id去查询一次,得到一个数组,再foreach数组拼装数据,细节不好描述,大致过程就是这样,不知道这样好不好。大家开发遇到这类问题怎么优化的?
继续补充
$sb_ids = $this->sgoods_bankroll->order('sb_id desc')->limit(50)->getField('sb_id',true);
$sb_ids = implode(',',$sb_ids);//所有sb_id
$where['br_sb_id'] = array('in',$sb_ids);
$sl_ids_array = $this->bankrollpop_relations->where($where)->getField('br_sb_id,br_sl_id');//sb_id和sl_id关联数组
$sl_ids = implode(',',$sl_ids_array);//所有sl_id
$where['sl_id'] = array('in',$sl_ids);
$sl_list = $this->settlementpop_list->where($where)->getField('sl_id,sl_schedule_name,sl_status');
$bankroll = $this->sgoods_bankroll->order('sb_id desc')->limit(50)->select();
foreach ($bankroll as $k=>&$v) {
$sl_id = $sl_ids_array[$v['sb_id']];
if($sl_id){
$v['sl_schedule_name'] = $sl_list[$sl_id]['sl_schedule_name'];
$v['sl_status'] = $sl_list[$sl_id]['sl_status'];
}
}
优化之后提高百倍!正好记录一篇博客: http://www.tantengvip.com/2015/07/relation-mysql/
sh002
answered 9 years, 10 months ago