題目:
查找各個部門當前(dept_manager.to_date='9999-01-01')領導當前(salaries.to_date='9999-01-01')薪水詳情以及其對應部門編號dept_no
(注:請以salaries表為主表進行查詢,輸出結果以salaries.emp_no升序排序,並且請注意輸出結果里面dept_no列是最后一列)
CREATE TABLE `salaries` (
`emp_no` int(11) NOT NULL, -- '員工編號',
`salary` int(11) NOT NULL,
`from_date` date NOT NULL,
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`from_date`));
CREATE TABLE `dept_manager` (
`emp_no` int(11) NOT NULL, -- '員工編號',
`salary` int(11) NOT NULL,
`from_date` date NOT NULL,
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`from_date`));
`dept_no` char(4) NOT NULL, -- '部門編號'
`emp_no` int(11) NOT NULL, -- '員工編號'
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`dept_no`));
程序:
SELECT a.*, b.dept_no FROM salaries AS a JOIN dept_manager AS b ON a.emp_no = b.emp_no WHERE b.to_date = '9999-01-01' AND a.to_date = '9999-01-01' ORDER BY a.emp_no ASC