1029作业

作业：
1. 查看岗位是teacher的员工姓名、年龄
select name,age from info where post='teacher';
2. 查看岗位是teacher且年龄大于30岁的员工姓名、年龄
select name,age from info where age>30;
3. 查看岗位是teacher且薪资在9000-1000范围内的员工姓名、年龄、薪资
select name,age,salary from info where salary between 9000 and 10000;
4. 查看岗位描述不为NULL的员工信息
select * from info where post is null;
5. 查看岗位是teacher且薪资是10000或9000或30000的员工姓名、年龄、薪资
select * from info where salary in (10000,9000,30000);
6. 查看岗位是teacher且薪资不是10000或9000或30000的员工姓名、年龄、薪资
select * from info where salary not in (10000,9000,30000);
7. 查看岗位是teacher且名字是jin开头的员工姓名、年薪
select name,salary from info where name like 'jin%';