作业：
''' 作业： 1. 查看岗位是teacher的员工姓名、年龄 2. 查看岗位是teacher且年龄大于30岁的员工姓名、年龄 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 4. 查看岗位描述不为NULL的员工信息 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 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 7. 查看岗位是teacher且名字是jin开头的员工姓名、年薪 ''' # 先创建一个数据库如下： mysql> select * from test; +----+-------+-----+---------+------------------+ | id | name | age | post | salary | +----+-------+-----+---------+------------------+ | 1 | jane | 26 | NULL | 35000.0000000000 | | 2 | nick | 18 | teacher | 20000.0000000000 | | 3 | tank | 25 | teacher | 25000.0000000000 | | 4 | jason | 23 | teacher | 23000.0000000000 | | 5 | engo | 25 | manager | 30000.0000000000 | +----+-------+-----+---------+------------------+ 5 rows in set (0.04 sec) # 1. 查看岗位是teacher的员工姓名、年龄 mysql> select name,age from test where post="teacher"; +-------+-----+ | name | age | +-------+-----+ | nick | 18 | | tank | 25 | | jason | 23 | +-------+-----+ 3 rows in set (0.10 sec) # 2. 查看岗位是teacher且年龄大于30岁的员工姓名、年龄 mysql> select name,age from test where post="teacher" and age>30; Empty set (0.00 sec) # 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 mysql> select name,age,salary from test where post="teacher" and salary between 1000 and 9000; Empty set (0.03 sec) # 4. 查看岗位描述不为NULL的员工信息 mysql> select * from where post != "NULL"; +----+-------+-----+---------+------------------+ | id | name | age | post | salary | +----+-------+-----+---------+------------------+ | 2 | nick | 18 | teacher | 20000.0000000000 | | 3 | tank | 25 | teacher | 25000.0000000000 | | 4 | jason | 23 | teacher | 23000.0000000000 | | 5 | engo | 25 | manager | 30000.0000000000 | +----+-------+-----+---------+------------------+ 4 rows in set (0.00 sec) # 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 mysql> select name,age,salary from test where post="teacher" and salary in (9000,10000,30000); Empty set (0.04 sec) # 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 mysql> select name,age,salary from test where post="teacher" and salary not in (9000,10000,30000); +-------+-----+------------------+ | name | age | salary | +-------+-----+------------------+ | nick | 18 | 20000.0000000000 | | tank | 25 | 25000.0000000000 | | jason | 23 | 23000.0000000000 | +-------+-----+------------------+ 3 rows in set (0.00 sec) # 7. 查看岗位是teacher且名字是jin开头的员工姓名、年薪 mysql> select name,salary from test where post="teacher" and name like "jin%"; Empty set (0.03 sec)