sql语句中sum方法的使用
$buy_log = (new \yii\db\Query())
->select(['total_num'=>"sum(total_num)",
'total_money'=>'sum(total_money)'])
->from(['pss_buy_log'])
->where(['order_id'=>304])
->one();
SUM() 函数
SUM() 函数返回数值列的总数。
SQL SUM() 语法
SELECT SUM(column_name) FROM table_name;