查询语句中count()的用法
$buy_log = (new \yii\db\Query())
->select(['total_num'=>"count(*)"])
->from(['pss_buy_log'])
->one();
return $buy_log;
$buy_log = (new \yii\db\Query())
->select(['total_num'=>"count(total_num)",
'total_money'=>'sum(total_money)'])
->from(['pss_buy_log'])
->where(['order_id'=>304])
->one();
SQL COUNT() 函数
COUNT() 函数返回匹配指定条件的行数。
SQL COUNT(column_name) 语法
COUNT(column_name) 函数返回指定列的值的数目(NULL 不计入):
SELECT COUNT(column_name) FROM table_name;
SQL COUNT() 语法
COUNT() 函数返回表中的记录数:
SELECT COUNT(*) FROM table_name