SQL11

题目描述

获取所有非manager员工当前的薪水情况，给出dept_no、emp_no以及salary ，当前表示to_date='9999-01-01'

    CREATE TABLE `dept_emp` (

    `emp_no` int(11) NOT NULL,

    `dept_no` char(4) NOT NULL,

    `from_date` date NOT NULL,

    `to_date` date NOT NULL,

    PRIMARY KEY (`emp_no`,`dept_no`));

    CREATE TABLE `dept_manager` (

    `dept_no` char(4) NOT NULL,

    `emp_no` int(11) NOT NULL,

    `from_date` date NOT NULL,

    `to_date` date NOT NULL,

    PRIMARY KEY (`emp_no`,`dept_no`));

    CREATE TABLE `employees` (

    `emp_no` int(11) NOT NULL,

    `birth_date` date NOT NULL,

    `first_name` varchar(14) NOT NULL,

    `last_name` varchar(16) NOT NULL,

    `gender` char(1) NOT NULL,

    `hire_date` date NOT NULL,

    PRIMARY KEY (`emp_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`));

示例：

dept_no    | emp_no|salary

d001    |10001  | 88958

d004    |10003  | 43311

解答思路：

先查出所有员工的工资情况，再排除掉非manager员工的记录

        1.select salary from salaries s left join dept_emp de on s.emp_no=de.emp_no where 

    s.to_date='9999-01-01'

        2.select de.dept_no,de.emp_no from dept_emp de left join dept_manager dr on 

    de.emp_no=dr.emp_no  where de.to_date='9999-01-01' and dr.emp_no is null

故答案为：

    select de.dept_no,de.emp_no,

    (select salary from salaries where 

     emp_no=de.emp_no and to_date='9999-01-01') as salary 

    from dept_emp de left join dept_manager dm 

    on de.emp_no=dm.emp_no  where de.to_date='9999-01-01' and dm.emp_no is null;