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 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));
解析：这个题主要是考察表的连结。
使用逗号连结
select em.last_name, em.first_name, de.dept_no
from employees as em, dept_emp as de
where em.emp_no = de.emp_no;
使用内部连结
select em.last_name, em.first_name, de.dept_no
from employees as em inner join dept_emp as de
where em.emp_no = de.emp_no;
