ThinkPHP 多表查询-如果字段A相同,则把字段B相加
ThinkPHP 多表查询-如果字段A相同,则把字段B相加
在一个项目中,需要查询表tr_product中的user_id字段,如果user_id相同,则把其对应的money字段相加,数据库截图如下:
实现代码:
$Model = D("Model');
$res =$Model->query("SELECT user_id,sum(money) from tr_order GROUP BY user_id");
结果:
array (size=2)
0 =>
array (size=2)
'user_id' => string '72' (length=2)
'sum(money)' => string '100677.00' (length=9)
1 =>
array (size=2)
'user_id' => string '89' (length=2)
'sum(money)' => string '34.00' (length=5)
技术扩展:
使用ThinkPHP提供的query函数,能够直接输入我们的sql语句。
GROUP BY 按user_id分组。
sum()函数:并对的money字段值进行累加。
A PHPer and a Linuxer
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