当有业务需求需要一次性循环n条数据,插入或更新数据库时,如果单纯的循环,插入/更新,会消耗太多的数据库资源
一下是一种简单的解决方案
数据库的insert 是可以批量更新的,当有大量数据循环insert时,可以将数据先保留不执行插入命令,到最后一条时一次性插入,例如tp的addAll()方法;
数据库的update 如果使用case when 的话,也是可以批量更新的,本人在百度上找到了一个基于tp的saveAll()方法,用于更新数据
本文主要讲关于批量insert;
例:
生成一个订单
正常情况的语句为:
1 2 3 4 5 | INSERT INTO order (`goods_id`,`num`,`price`) VALUES (1,1,'10.00');//封装成函数function add_order($goods_id,$num,$price){$db->query("INSERT INTO order (`goods_id`,`num`,`price`) VALUES ($goods_id,$num,$price)");} |
假设有一个用户,一次性将购物车的1000个商品结算成订单,生成1000个订单时;
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | for ($i=0;$i<1000;$i++){$db->query("INSERT INTO order (`goods_id`,`num`,`price`) VALUES ($goods_id,$num,$price)");}//这样的话会导致服务器资源占用过大,网站卡死//所以,我们可以$sql = "INSERT INTO order (`goods_id`,`num`,`price`) VALUES ";for ($i=0;$i<1000;$i++){ if($i==0){ $sql.="($goods_id,$num,$price)"; }else{ $sql.=",($goods_id,$num,$price)"; }}$db->query($sql); |
大概意思就是这样了,批量更新实现比较麻烦一点,就不发了,以下是批量更新的sql执行语句
1 | UPDATE tiyan.dm_user_cupboard SET `res_id` = CASE `id` WHEN 1041 THEN '1' WHEN 1058 THEN '1' WHEN 1055 THEN '1' END,`food_code` = CASE `id` WHEN 1041 THEN '68' WHEN 1058 THEN '47' WHEN 1055 THEN '49' END,`food_name` = CASE `id` WHEN 1041 THEN '红枣' WHEN 1058 THEN '莲藕' WHEN 1055 THEN '洋葱' END,`num` = CASE `id` WHEN 1041 THEN '2' WHEN 1058 THEN '3' WHEN 1055 THEN '2' END,`level` = CASE `id` WHEN 1041 THEN '2' WHEN 1058 THEN '2' WHEN 1055 THEN '2' END,`update_time` = CASE `id` WHEN 1041 THEN '2017-12-09 21:40:06' WHEN 1058 THEN '2017-12-09 21:40:06' WHEN 1055 THEN '2017-12-09 21:40:06' END WHERE id IN ( 1041,1058,1055 ) |
附带基于tp的saveAll()
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | //批量更新public function saveAll($datas,$model){ ( $model || $model=$this->tableName); $model=empty($model)?$this->name:$model; $sql = ''; //Sql $lists = []; //记录集$lists $pk = $this->getPk();//获取主键 foreach ($datas as $data) { foreach ($data as $key=>$value) { if($pk===$key){ $ids[]=$value; }else{ $lists[$key].= sprintf("WHEN %u THEN '%s' ",$data[$pk],$value); } } } foreach ($lists as $key => $value) { $sql.= sprintf("`%s` = CASE `%s` %s END,",$key,$pk,$value); } $sql = sprintf('UPDATE __%s__ SET %s WHERE %s IN ( %s )',strtoupper($model),rtrim($sql,','),$pk,implode(',',$ids)); return M()->execute($sql);} |
