数据代码见上篇。

dept：部门表emp：员工表salgrade ：工资等级表
deptno：部门编号empno：员工编号grade：等级
dname：部门名称ename:员工名字losal：最低薪资
loc：部门位置job：工作岗位hisal：最高薪资
mgr：上级领导编号
hiredate：入职时间
sal：月薪
comm：补助/津贴
deptno：部门编号

列出所有“CLERK”(办事员)的姓名和部门名称、部门人数

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
# （1）工作岗位为“CLERK”的信息
select d.deptno,d.dname,e.ename
from emp e
join dept d
on e.deptno=d.deptno
where e.job='CLERK';
+--------+------------+--------+
| deptno | dname      | ename  |
+--------+------------+--------+
|     20 | RESEARCH   | SMITH  |
|     20 | RESEARCH   | ADAMS  |
|     30 | SALES      | JAMES  |
|     10 | ACCOUNTING | MILLER |
+--------+------------+--------+

# （2）每个部门的员工数量
select e.deptno,count(e.ename) as totalEmp
from emp e
group by e.deptno;
+--------+----------+
| deptno | totalEmp |
+--------+----------+
|     20 |        5 |
|     30 |        6 |
|     10 |        3 |
+--------+----------+

# （3）两张表连接
select t.deptno,t.dname,t.ename,f.totalEmp
from (select d.deptno,d.dname,e.ename from emp e 
    join dept d on e.deptno=d.deptno where e.job='CLERK') t
join (select e.deptno,count(e.ename) as totalEmp from emp e group by e.deptno) f
on t.deptno=f.deptno;
+--------+------------+--------+----------+
| deptno | dname      | ename  | totalEmp |
+--------+------------+--------+----------+
|     20 | RESEARCH   | SMITH  |        5 |
|     20 | RESEARCH   | ADAMS  |        5 |
|     30 | SALES      | JAMES  |        6 |
|     10 | ACCOUNTING | MILLER |        3 |
+--------+------------+--------+----------+

列出最低薪水大于1500的各种工作和此工作的全部雇员人数

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
# （1）每种工作岗位的最低薪水
select e.job,min(sal) minSal
from emp e
group by e.job;
+-----------+---------+
| job       | minSal  |
+-----------+---------+
| CLERK     |  800.00 |
| SALESMAN  | 1250.00 |
| MANAGER   | 2450.00 |
| ANALYST   | 3000.00 |
| PRESIDENT | 5000.00 |
+-----------+---------+

# （2）每个工作岗位最低薪水大于1500的工作人数
select e.job,min(sal) minSal,count(e.ename)
from emp e
group by e.job
having minSal>1500;
+-----------+---------+----------------+
| job       | minSal  | count(e.ename) |
+-----------+---------+----------------+
| MANAGER   | 2450.00 |              3 |
| ANALYST   | 3000.00 |              2 |
| PRESIDENT | 5000.00 |              1 |
+-----------+---------+----------------+

列出在部门“SALES”<销售部>工作的员工姓名

（假定不知道销售部门的部门编号）

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
# （1）部门名为"SALES"的部门编号
select deptno from dept where dname="SALES";
+--------+
| deptno |
+--------+
|     30 |
+--------+

# （2）查询员工姓名
select ename from emp e where deptno=(select deptno from dept where dname="SALES");
+--------+
| ename  |
+--------+
| ALLEN  |
| WARD   |
| MARTIN |
| BLAKE  |
| TURNER |
| JAMES  |
+--------+

列出薪资高于公司平均薪资的所有员工，所在部门、上级领导、雇员的工资等级

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
# （1）公司平均薪资
select avg(sal) avgsal from emp;
+-------------+
| avgsal      |
+-------------+
| 2073.214286 |
+-------------+

# （2）第一个连接：部门名字
#      第二个左连接：emp表看成两张表，列出员工对应的上级领导
#      第三个连接：工资等级
select d.dname,e.ename,b.ename as leadername,grade
from emp e join dept d on e.deptno=d.deptno
left join emp b on e.mgr=b.empno
join salgrade s on e.sal between s.losal and s.hisal
where e.sal>(select avg(sal) avgsal from emp);
+------------+-------+------------+-------+
| dname      | ename | leadername | grade |
+------------+-------+------------+-------+
| RESEARCH   | FORD  | JONES      |     4 |
| RESEARCH   | SCOTT | JONES      |     4 |
| ACCOUNTING | CLARK | KING       |     4 |
| SALES      | BLAKE | KING       |     4 |
| RESEARCH   | JONES | KING       |     4 |
| ACCOUNTING | KING  | NULL       |     5 |
+------------+-------+------------+-------+

列出与(ename)“SCOTT”从事相同工作的所有员工和部门名称

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
# （1）查询出“SCOTT”的工作岗位
select job from emp where ename="SCOTT";
+---------+
| job     |
+---------+
| ANALYST |
+---------+

# （2）
select d.dname,e.*
from emp e
join dept d
on e.deptno=d.deptno
where e.job=(select job from emp where ename="SCOTT");
+----------+-------+-------+---------+------+------------+---------+------+--------+
| dname    | EMPNO | ENAME | JOB     | MGR  | HIREDATE   | SAL     | COMM | DEPTNO |
+----------+-------+-------+---------+------+------------+---------+------+--------+
| RESEARCH |  7788 | SCOTT | ANALYST | 7566 | 1987-04-19 | 3000.00 | NULL |     20 |
| RESEARCH |  7902 | FORD  | ANALYST | 7566 | 1981-12-03 | 3000.00 | NULL |     20 |
+----------+-------+-------+---------+------+------------+---------+------+--------+

列出薪资等于部门30中工作的员工的薪资的其他员工的姓名和薪资

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
# （1）部门30中工作的员工的薪资
select distinct sal from emp where deptno=30;
+---------+
| sal     |
+---------+
| 1600.00 |
| 1250.00 |
| 2850.00 |
| 1500.00 |
|  950.00 |
+---------+

# （2）薪资与以上的相同，排除部门30
select ename,sal from emp
where sal in (select distinct sal from emp where deptno=30)
and deptno !=30;
Empty set (0.00 sec)

列出薪资高于在部门30中工作的员工的薪资的员工的姓名和薪资、部门名称

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
# （1）部门30中的员工最高工资
select max(sal) from emp where deptno=30;
+----------+
| max(sal) |
+----------+
|  2850.00 |
+----------+

# （2）高于最高工资的其他员工
select deptno,ename,sal from emp
where sal>(select max(sal) from emp where deptno=30)
and deptno!=30;
+--------+-------+---------+
| deptno | ename | sal     |
+--------+-------+---------+
|     20 | JONES | 2975.00 |
|     20 | SCOTT | 3000.00 |
|     10 | KING  | 5000.00 |
|     20 | FORD  | 3000.00 |
+--------+-------+---------+

# （3）连接dept表
select d.dname,t.ename,t.sal 
from (select deptno,ename,sal from emp
        where sal>(select max(sal) from emp where deptno=30)
        and deptno!=30) t
join dept d
on t.deptno=d.deptno;
+------------+-------+---------+
| dname      | ename | sal     |
+------------+-------+---------+
| RESEARCH   | JONES | 2975.00 |
| RESEARCH   | SCOTT | 3000.00 |
| ACCOUNTING | KING  | 5000.00 |
| RESEARCH   | FORD  | 3000.00 |
+------------+-------+---------+

列出在每个部门工作的员工数量、平均工资和平均服务期限

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
# （1）当前日期、服务期限
select ename,(to_days(now())-to_days(hiredate))/365 as serveyear from emp;
+--------+-----------+
| ename  | serveyear |
+--------+-----------+
| SMITH  |   42.3589 |
| ALLEN  |   42.1808 |
| WARD   |   42.1753 |
| JONES  |   42.0685 |
| MARTIN |   41.5781 |
| BLAKE  |   41.9890 |
| CLARK  |   41.8822 |
| SCOTT  |   36.0192 |
| KING   |   41.4411 |
| TURNER |   41.6329 |
| ADAMS  |   35.9260 |
| JAMES  |   41.3973 |
| FORD   |   41.3973 |
| MILLER |   41.2575 |
+--------+-----------+

# （2）每个部门的员工数量、平均工资、平均服务期限
select deptno,count(ename),avg(sal) avgsal,
        avg((to_days(now())-to_days(hiredate))/365) avgserveyear
from emp group by deptno;
+--------+--------------+-------------+--------------+
| deptno | count(ename) | avgsal      | avgserveyear |
+--------+--------------+-------------+--------------+
|     20 |            5 | 2175.000000 |  39.55398000 |
|     30 |            6 | 1566.666667 |  41.82556667 |
|     10 |            3 | 2916.666667 |  41.52693333 |
+--------+--------------+-------------+--------------+

列出所有员工的姓名、部门名称和工资

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
# 右连接：员工的姓名、部门名称和工资
select d.dname,e.ename,e.sal
from emp e
right join dept d
on e.deptno=d.deptno;
+------------+--------+---------+
| dname      | ename  | sal     |
+------------+--------+---------+
| ACCOUNTING | MILLER | 1300.00 |
| ACCOUNTING | KING   | 5000.00 |
| ACCOUNTING | CLARK  | 2450.00 |
| RESEARCH   | FORD   | 3000.00 |
| RESEARCH   | ADAMS  | 1100.00 |
| RESEARCH   | SCOTT  | 3000.00 |
| RESEARCH   | JONES  | 2975.00 |
| RESEARCH   | SMITH  |  800.00 |
| SALES      | JAMES  |  950.00 |
| SALES      | TURNER | 1500.00 |
| SALES      | BLAKE  | 2850.00 |
| SALES      | MARTIN | 1250.00 |
| SALES      | WARD   | 1250.00 |
| SALES      | ALLEN  | 1600.00 |
| OPERATIONS | NULL   |    NULL |
+------------+--------+---------+

列出所有部门的详细信息和人数

1
2
3
4
5
6
7
8
9
10
11
12
13
select d.deptno,d.dname,d.loc,count(ename) totalename
from emp e
right join dept d
on d.deptno=e.deptno
group by deptno;
+--------+------------+----------+------------+
| deptno | dname      | loc      | totalename |
+--------+------------+----------+------------+
|     10 | ACCOUNTING | NEW YORK |          3 |
|     20 | RESEARCH   | DALLAS   |          5 |
|     30 | SALES      | CHICAGO  |          6 |
|     40 | OPERATIONS | BOSTON   |          0 |
+--------+------------+----------+------------+

列出各种工作的最低工资及从事此工作的雇员姓名

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
# （1）每个工作岗位的最低工资
select e.job,min(e.sal) minsal
from emp e 
group by e.job;
+-----------+---------+
| job       | minsal  |
+-----------+---------+
| CLERK     |  800.00 |
| SALESMAN  | 1250.00 |
| MANAGER   | 2450.00 |
| ANALYST   | 3000.00 |
| PRESIDENT | 5000.00 |
+-----------+---------+

# （2）匹配每个员工姓名
select e.ename,e.job,e.sal
from emp e 
join (select e.job,min(e.sal) minsal from emp e group by e.job) t
on e.job=t.job
where e.sal=t.minsal;
+--------+-----------+---------+
| ename  | job       | sal     |
+--------+-----------+---------+
| SMITH  | CLERK     |  800.00 |
| WARD   | SALESMAN  | 1250.00 |
| MARTIN | SALESMAN  | 1250.00 |
| CLARK  | MANAGER   | 2450.00 |
| SCOTT  | ANALYST   | 3000.00 |
| KING   | PRESIDENT | 5000.00 |
| FORD   | ANALYST   | 3000.00 |
+--------+-----------+---------+

列出各个部门MANAGER的最低薪资

1
2
3
4
5
6
7
8
9
10
11
12
# （1） 匹配工作岗位中的MANAGER
select e.deptno,min(sal) minsal
from emp e
where e.job="MANAGER"
group by e.deptno;
+--------+---------+
| deptno | minsal  |
+--------+---------+
|     20 | 2975.00 |
|     30 | 2850.00 |
|     10 | 2450.00 |
+--------+---------+

列出所有员工的年工资，按年薪从低到高排序

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
select ename,(sal+ifnull(comm,0))*12 as yearsal
from emp order by yearsal asc;
+--------+----------+
| ename  | yearsal  |
+--------+----------+
| SMITH  |  9600.00 |
| JAMES  | 11400.00 |
| ADAMS  | 13200.00 |
| MILLER | 15600.00 |
| TURNER | 18000.00 |
| WARD   | 21000.00 |
| ALLEN  | 22800.00 |
| CLARK  | 29400.00 |
| MARTIN | 31800.00 |
| BLAKE  | 34200.00 |
| JONES  | 35700.00 |
| SCOTT  | 36000.00 |
| FORD   | 36000.00 |
| KING   | 60000.00 |
+--------+----------+

列出员工领导的薪资超过3000的员工名称和领导名称

1
2
3
4
5
6
7
8
9
10
11
12
select e.ename,b.ename as leadername
from emp e
join emp b
on e.mgr=b.empno
where b.sal>3000;
+-------+------------+
| ename | leadername |
+-------+------------+
| JONES | KING       |
| BLAKE | KING       |
| CLARK | KING       |
+-------+------------+

列出部门名称中带“S”字符的部门员工的工资合计、部门人数

1
2
3
4
5
6
7
8
9
10
11
12
select d.dname,sum(e.sal) sumavg,count(e.ename) totalemp
from emp e
join dept d
on e.deptno=d.deptno
where d.dname like '%s%'
group by d.dname;
+----------+----------+----------+
| dname    | sumavg   | totalemp |
+----------+----------+----------+
| RESEARCH | 10875.00 |        5 |
| SALES    |  9400.00 |        6 |
+----------+----------+----------+

给任职日期超过30年的员工加薪10%

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
# 复制一张表
create table emp_bark as select * from emp;
+-------+--------+-----------+------+------------+---------+---------+--------+
| EMPNO | ENAME  | JOB       | MGR  | HIREDATE   | SAL     | COMM    | DEPTNO |
+-------+--------+-----------+------+------------+---------+---------+--------+
|  7369 | SMITH  | CLERK     | 7902 | 1980-12-17 |  800.00 |    NULL |     20 |
|  7499 | ALLEN  | SALESMAN  | 7698 | 1981-02-20 | 1600.00 |  300.00 |     30 |
|  7521 | WARD   | SALESMAN  | 7698 | 1981-02-22 | 1250.00 |  500.00 |     30 |
|  7566 | JONES  | MANAGER   | 7839 | 1981-04-02 | 2975.00 |    NULL |     20 |
|  7654 | MARTIN | SALESMAN  | 7698 | 1981-09-28 | 1250.00 | 1400.00 |     30 |
|  7698 | BLAKE  | MANAGER   | 7839 | 1981-05-01 | 2850.00 |    NULL |     30 |
|  7782 | CLARK  | MANAGER   | 7839 | 1981-06-09 | 2450.00 |    NULL |     10 |
|  7788 | SCOTT  | ANALYST   | 7566 | 1987-04-19 | 3000.00 |    NULL |     20 |
|  7839 | KING   | PRESIDENT | NULL | 1981-11-17 | 5000.00 |    NULL |     10 |
|  7844 | TURNER | SALESMAN  | 7698 | 1981-09-08 | 1500.00 |    0.00 |     30 |
|  7876 | ADAMS  | CLERK     | 7788 | 1987-05-23 | 1100.00 |    NULL |     20 |
|  7900 | JAMES  | CLERK     | 7698 | 1981-12-03 |  950.00 |    NULL |     30 |
|  7902 | FORD   | ANALYST   | 7566 | 1981-12-03 | 3000.00 |    NULL |     20 |
|  7934 | MILLER | CLERK     | 7782 | 1982-01-23 | 1300.00 |    NULL |     10 |
+-------+--------+-----------+------+------------+---------+---------+--------+

# 更新表
update emp_bark set sal =sal*1.1 where(to_days(now())-to_days(hiredate))/365>30;
Query OK, 14 rows affected (0.13 sec)
+-------+--------+-----------+------+------------+---------+---------+--------+
| EMPNO | ENAME  | JOB       | MGR  | HIREDATE   | SAL     | COMM    | DEPTNO |
+-------+--------+-----------+------+------------+---------+---------+--------+
|  7369 | SMITH  | CLERK     | 7902 | 1980-12-17 |  880.00 |    NULL |     20 |
|  7499 | ALLEN  | SALESMAN  | 7698 | 1981-02-20 | 1760.00 |  300.00 |     30 |
|  7521 | WARD   | SALESMAN  | 7698 | 1981-02-22 | 1375.00 |  500.00 |     30 |
|  7566 | JONES  | MANAGER   | 7839 | 1981-04-02 | 3272.50 |    NULL |     20 |
|  7654 | MARTIN | SALESMAN  | 7698 | 1981-09-28 | 1375.00 | 1400.00 |     30 |
|  7698 | BLAKE  | MANAGER   | 7839 | 1981-05-01 | 3135.00 |    NULL |     30 |
|  7782 | CLARK  | MANAGER   | 7839 | 1981-06-09 | 2695.00 |    NULL |     10 |
|  7788 | SCOTT  | ANALYST   | 7566 | 1987-04-19 | 3300.00 |    NULL |     20 |
|  7839 | KING   | PRESIDENT | NULL | 1981-11-17 | 5500.00 |    NULL |     10 |
|  7844 | TURNER | SALESMAN  | 7698 | 1981-09-08 | 1650.00 |    0.00 |     30 |
|  7876 | ADAMS  | CLERK     | 7788 | 1987-05-23 | 1210.00 |    NULL |     20 |
|  7900 | JAMES  | CLERK     | 7698 | 1981-12-03 | 1045.00 |    NULL |     30 |
|  7902 | FORD   | ANALYST   | 7566 | 1981-12-03 | 3300.00 |    NULL |     20 |
|  7934 | MILLER | CLERK     | 7782 | 1982-01-23 | 1430.00 |    NULL |     10 |
+-------+--------+-----------+------+------------+---------+---------+--------+

题目来源： 动力节点_MySQL_124_34道经典SQL试题_第1题_哔哩哔哩_bilibili