181. 超过经理收入的员工
表:Employee
+-------------+---------+ | Column Name | Type | +-------------+---------+ | id | int | | name | varchar | | salary | int | | managerId | int | +-------------+---------+ Id是该表的主键。 该表的每一行都表示雇员的ID、姓名、工资和经理的ID。
编写一个SQL查询来查找收入比经理高的员工。
以 任意顺序 返回结果表。
查询结果格式如下所示。
示例 1:
输入: Employee 表: +----+-------+--------+-----------+ | id | name | salary | managerId | +----+-------+--------+-----------+ | 1 | Joe | 70000 | 3 | | 2 | Henry | 80000 | 4 | | 3 | Sam | 60000 | Null | | 4 | Max | 90000 | Null | +----+-------+--------+-----------+ 输出: +----------+ | Employee | +----------+ | Joe | +----------+ 解释: Joe 是唯一挣得比经理多的雇员。
SELECT a.name AS Employee FROM Employee a, Employee b WHERE a.managerId = b.id AND a.salary > b.salary;
184. 部门工资最高的员工
表: Employee
+--------------+---------+ | 列名 | 类型 | +--------------+---------+ | id | int | | name | varchar | | salary | int | | departmentId | int | +--------------+---------+ id是此表的主键列。 departmentId是Department表中ID的外键。 此表的每一行都表示员工的ID、姓名和工资。它还包含他们所在部门的ID。
表: Department
+-------------+---------+ | 列名 | 类型 | +-------------+---------+ | id | int | | name | varchar | +-------------+---------+ id是此表的主键列。 此表的每一行都表示一个部门的ID及其名称。
编写SQL查询以查找每个部门中薪资最高的员工。
按 任意顺序 返回结果表。
查询结果格式如下例所示。
示例 1:
输入: Employee 表: +----+-------+--------+--------------+ | id | name | salary | departmentId | +----+-------+--------+--------------+ | 1 | Joe | 70000 | 1 | | 2 | Jim | 90000 | 1 | | 3 | Henry | 80000 | 2 | | 4 | Sam | 60000 | 2 | | 5 | Max | 90000 | 1 | +----+-------+--------+--------------+ Department 表: +----+-------+ | id | name | +----+-------+ | 1 | IT | | 2 | Sales | +----+-------+ 输出: +------------+----------+--------+ | Department | Employee | Salary | +------------+----------+--------+ | IT | Jim | 90000 | | Sales | Henry | 80000 | | IT | Max | 90000 | +------------+----------+--------+ 解释:Max 和 Jim 在 IT 部门的工资都是最高的,Henry 在销售部的工资最高。
select Department.name as Department,Employee.name as Employee,salary from Employee left join Department on Employee.departmentId = Department.id where (Employee.departmentId,salary) in (select departmentId,max(salary) from Employee group by departmentId)
511. 游戏玩法分析 I
活动表 Activity:
+--------------+---------+ | Column Name | Type | +--------------+---------+ | player_id | int | | device_id | int | | event_date | date | | games_played | int | +--------------+---------+ 表的主键是 (player_id, event_date)。 这张表展示了一些游戏玩家在游戏平台上的行为活动。 每行数据记录了一名玩家在退出平台之前,当天使用同一台设备登录平台后打开的游戏的数目(可能是 0 个)。
写一条 SQL 查询语句获取每位玩家 第一次登陆平台的日期。
查询结果的格式如下所示:
Activity 表: +-----------+-----------+------------+--------------+ | player_id | device_id | event_date | games_played | +-----------+-----------+------------+--------------+ | 1 | 2 | 2016-03-01 | 5 | | 1 | 2 | 2016-05-02 | 6 | | 2 | 3 | 2017-06-25 | 1 | | 3 | 1 | 2016-03-02 | 0 | | 3 | 4 | 2018-07-03 | 5 | +-----------+-----------+------------+--------------+ Result 表: +-----------+-------------+ | player_id | first_login | +-----------+-------------+ | 1 | 2016-03-01 | | 2 | 2017-06-25 | | 3 | 2016-03-02 | +-----------+-------------+
select player_id, min(event_date) as first_login from Activity group by player_id
620. 有趣的电影
某城市开了一家新的电影院,吸引了很多人过来看电影。该电影院特别注意用户体验,专门有个 LED显示板做电影推荐,上面公布着影评和相关电影描述。
作为该电影院的信息部主管,您需要编写一个 SQL查询,找出所有影片描述为非 boring (不无聊) 的并且 id 为奇数 的影片,结果请按等级 rating 排列。
例如,下表 cinema:
+---------+-----------+--------------+-----------+ | id | movie | description | rating | +---------+-----------+--------------+-----------+ | 1 | War | great 3D | 8.9 | | 2 | Science | fiction | 8.5 | | 3 | irish | boring | 6.2 | | 4 | Ice song | Fantacy | 8.6 | | 5 | House card| Interesting| 9.1 | +---------+-----------+--------------+-----------+
对于上面的例子,则正确的输出是为:
+---------+-----------+--------------+-----------+ | id | movie | description | rating | +---------+-----------+--------------+-----------+ | 5 | House card| Interesting| 9.1 | | 1 | War | great 3D | 8.9 | +---------+-----------+--------------+-----------+
select * from cinema where description != "boring" and id%2 != 0 order by rating desc
1068. 产品销售分析 I
销售表 Sales:
+-------------+-------+ | Column Name | Type | +-------------+-------+ | sale_id | int | | product_id | int | | year | int | | quantity | int | | price | int | +-------------+-------+ (sale_id, year) 是销售表 Sales 的主键. product_id 是关联到产品表 Product 的外键. 注意: price 表示每单位价格
产品表 Product:
+--------------+---------+ | Column Name | Type | +--------------+---------+ | product_id | int | | product_name | varchar | +--------------+---------+ product_id 是表的主键.
写一条SQL 查询语句获取 Sales 表中所有产品对应的 产品名称 product_name 以及该产品的所有 售卖年份 year 和 价格 price 。
查询结果中的顺序无特定要求。
查询结果格式示例如下:
Sales 表:
+---------+------------+------+----------+-------+
| sale_id | product_id | year | quantity | price |
+---------+------------+------+----------+-------+
| 1 | 100 | 2008 | 10 | 5000 |
| 2 | 100 | 2009 | 12 | 5000 |
| 7 | 200 | 2011 | 15 | 9000 |
+---------+------------+------+----------+-------+
Product 表:
+------------+--------------+
| product_id | product_name |
+------------+--------------+
| 100 | Nokia |
| 200 | Apple |
| 300 | Samsung |
+------------+--------------+
Result 表:
+--------------+-------+-------+
| product_name | year | price |
+--------------+-------+-------+
| Nokia | 2008 | 5000 |
| Nokia | 2009 | 5000 |
| Apple | 2011 | 9000 |
+--------------+-------+-------+
select p.product_name,s.year,s.price from Product p left join Sales s on p.product_id=s.product_id