题目描述: 查找各个部门当前(to_date=‘9999-01-01’)领导当前薪水详情以及其对应部门编号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 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));
思路: 两张表的内容=inner join 或 join 两张表需要一个桥梁搭建起来=on 两张表的to_date条件需要同时满足需要 and
代码:
select d
.dept_no
,d
.emp_no
,s
.salary
from salaries
as s
inner join dept_manager
as d
on s
.emp_no
= d
.emp_no
and
d
.to_date
='9999-01-01'
and
s
.to_date
='9999-01-01'
输出描述: