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题解 | #返回订单数量总和不小于100的所有订单的订单号#

SELECT a.order_num FROM (SELECT order_num,SUM(quantity)AS num FROM OrderItems GROUP BY order_num)AS a WHERE num>100 ORDER BY a.order_num; 可用子查询先将符合...

Mysql

2022-06-24

0 272

题解 | #统计每种性别的人数#

SELECT SUBSTRING(profile FROM 15 FOR 6)AS gender,COUNT(device_id) FROM user_submit GROUP BY gender; profile FROM 15 FOR 6 /*字符串的提取，SUBSTRING(对象字符串 F...

Mysql

2022-02-16

0 0