《数据库SQL实战》查找当前薪水详情以及部门编号dept_no

题目：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

));

select a.emp_no,a.salary,a.from_date,a.to_date,b.dept_no
from salaries a
left join dept_manager b
on a.emp_no=b.emp_no
where a.to_date='9999-01-01'
and b.to_date='9999-01-01'