Carl_ZhangJH

2023年4月25日

摘要：訂單最多的客戶 select customer_number from Orders group by customer_number having count(order_number) = ( select count(order_number) from Orders group by cus 阅读全文

posted @ 2023-04-25 15:36 Carl_ZhangJH 阅读(13) 评论(0) 推荐(0)

leetcode 584 尋找用戶推薦人

摘要：尋找用戶推薦人 select name from customer where referee_id <> 2 or referee_id is null 阅读全文

posted @ 2023-04-25 15:12 Carl_ZhangJH 阅读(14) 评论(0) 推荐(0)

leetcode 570 至少有5名直接下屬的經理

摘要：至少有5名直接下屬的經理子查詢 select `name` from Employee where id in ( select managerId from Employee group by managerId having count(managerId) >= 5 ) 自連接 select 阅读全文

posted @ 2023-04-25 14:29 Carl_ZhangJH 阅读(17) 评论(0) 推荐(0)

2023年4月24日

leetcode 550 游戏玩法分析IV

摘要：游戏玩法分析 select round(avg(a.event_date is not null), 2) as fraction from (select player_id, min(event_date) as event_date from activity group by player_ 阅读全文

posted @ 2023-04-24 17:59 Carl_ZhangJH 阅读(30) 评论(0) 推荐(0)

leetcode 511 游戏玩法分析 I

摘要：游戏玩法分析 select player_id , min(event_date) as first_login from Activity group by player_id order by player_id asc == 阅读全文

posted @ 2023-04-24 11:07 Carl_ZhangJH 阅读(145) 评论(0) 推荐(0)

2023年4月23日

leetcode 262 行程和用戶

摘要：行程和用戶 SELECT t.`request_at` AS `Day`, ROUND(SUM(IF(t.status = 'completed', 0, 1))/COUNT(t.status) ,2) AS `Cancellation Rate` FROM Trips AS t LEFT JOIN 阅读全文

posted @ 2023-04-23 17:19 Carl_ZhangJH 阅读(21) 评论(0) 推荐(0)

2023年4月12日

leetcode 197 上升的温度

摘要：上升的温度 date_add（interval expr type）使用日期相加函数 select w1.id from Weather w1 left join Weather w2 on w1.recordDate = date_add(w2.recordDate, interval 1 da 阅读全文

posted @ 2023-04-12 18:03 Carl_ZhangJH 阅读(21) 评论(0) 推荐(0)

leetcode 196 删除重复的电子邮箱

摘要：删除重复的电子邮箱 mysql 来说，inner join 是在做笛卡尔积 delete p1 from Person p1 inner join Person p2 on p1.email = p2.email and p1.Id > p2.Id delete p1 FROM person p1 阅读全文

posted @ 2023-04-12 17:02 Carl_ZhangJH 阅读(16) 评论(0) 推荐(0)

leetcode 185 部门工资前三高的所有员工

摘要：部门工资前三高的所有员工 select d.name as Department, e.name as Employee, e.salary as Salary from Employee e left join Department d on e.departmentId = d.Id where 阅读全文

posted @ 2023-04-12 15:35 Carl_ZhangJH 阅读(21) 评论(0) 推荐(0)

2023年4月11日

leetcode 184 部门工资最高的员工

摘要：部门工资最高的员工 select d.name as Department, e.name as Employee, e.salary as Salary from Employee e left join Department d on e.departmentId = d.id where (e 阅读全文

posted @ 2023-04-11 16:06 Carl_ZhangJH 阅读(14) 评论(0) 推荐(0)

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