【⽜客SQL】SQL22统计各个部门的⼯资记录数题⽬描述
描述
有⼀个部门表departments简况如下:
有⼀个，部门员⼯关系表dept_emp简况如下:
有⼀个薪⽔表salaries简况如下:
请你统计各个部门的⼯资记录数，给出部门编码dept_no、部门名称dept_name以及部门在salaries表⾥⾯有多少条记录sum，按照dept_no升序排序，以上例⼦输出如下:
⽰例1
输⼊：
drop table if exists  `departments` ;
drop table if exists  `dept_emp` ;
drop table if exists  `salaries` ;
CREATE TABLE `departments` (
`dept_no` char(4) NOT NULL,
`dept_name` varchar(40) NOT NULL,
PRIMARY KEY (`dept_no`));
CREATE TABLE `dept_emp` (
`emp_no` int(11) NOT NULL,
`dept_no` char(4) NOT NULL,
张馨予`from_date` date NOT NULL,
金泫雅 金晓钟
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`dept_no`));
CREATE TABLE `salaries` (
`emp_no` int(11) NOT NULL,
`salary` int(11) NOT NULL,
`from_date` date NOT NULL,
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`from_date`));
INSERT INTO departments VALUES('d001','Marketing');
INSERT INTO departments VALUES('d002','Finance');
INSERT INTO dept_emp VALUES(10001,'d001','2001-06-22','9999-01-01'); INSERT INTO dept_emp VALUES(10002,'d001','1996-08-03','9999-01-01'); INSERT INTO dept_emp VALUES(10003,'d002','1996-08-03','9999-01-01'); INSERT INTO salaries VALUES(10001,85097,'2001-06-22','2002-06-22'); INSERT INTO salaries VALUES(10001,88958,'20
02-06-22','9999-01-01'); INSERT INTO salaries VALUES(10002,72527,'1996-08-03','9999-01-01'); INSERT INTO salaries VALUES(10003,32323,'1996-08-03','9999-01-01')；复制
输出：
d001|Marketing|3屠洪纲>李斯特 爱之梦
d002|Finance|1
题解半城山半城水
运⾏时间：13ms
超过80.58% ⽤Sqlite提交的代码
占⽤内存：3456KB
超过17.53%⽤Sqlite提交的代码
SELECT d1.dept_no, d1.dept_name, COUNT(d1.dept_no)
FROM departments AS d1 JOIN (
心愿歌词p_no, d2.dept_no
FROM dept_emp AS d2 JOIN salaries AS s
p_no = s.emp_no
) AS t
ON d1.dept_no = t.dept_no
GROUP BY d1.dept_no
;