1、 查詢Departments表中的所有記錄；
Use yggl;
Select * from departments;
2、 查詢Employees表中員工的姓名，地址和電話；
Select name,address,phonenumber
From employees;
3、 查詢Employees表中員工的部門號和性別，要求消除重復行；
Select distinct departmentid,sex
From employees;
4、 查詢EmployeeID為000001的員工地址和電話，要求顯示列名為address、telephone；
Select address as address,phonenumber as telephone
From employees
Where employeeid = ‘000001’;
5、 查詢Employees表中員工的姓名和性別，要求性別為1時顯示為“男”，為0時顯示為“女”；
Select name,
Case
When sex=1 then ‘男’
When sex=0 then ‘女’
End as sex
From employees;
6、 計算Salary表中所有員工收入的平均值、最大值和最小值；
Select avg(income),max(income),min(income)
From salary;
7、 計算所有員工的總支出；
Select sum(outcome) as ‘總支出’
From salary;
8、 計算員工總數；
Select count(*) as ‘員工總數’
From employees;
9、 顯示女員工的地址和電話；
Select name as ‘姓名’,address as ‘地址’,phonenumber as ‘電話’
From employees
Where sex =0;
10、 查詢月收入高於2000元的員工編號；
Select employeeid
From salary
Where income>2000;
11、 查詢1970年以后出生的員工的姓名和地址；
Select name as’姓名’，address as ‘地址’
From employees
Where birthday >’197-12-31’;
12、 查詢地址中含有“中山”的員工編號和部門號；
Select name as’姓名’，employeeid as ‘員工編號’,departmentid as ‘部門號’
From employees
Where address like ‘中山%’;
13、 查詢員工編號中倒數第二個數字為0的姓名、地址和學歷；
Select name,address,education
From employees
Where employeeid like ‘%0_’;
14、 找出所有收入在2000-3000元之間的員工編號和姓名；
Select name as ’姓名’，salary.employeeid as ‘員工編號’
From employees,salary
Where employees.employeeid=salary.employeeid
And income>2000 and income<3000;
15、 查詢所有在部門“1”或“2” 工作的員工編號。
Select name as’姓名’，employeeid as ‘員工編號’
From employees
Where departmentid=1 or departmentid=2;
