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题目

获取所有非manager的员工emp_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`));如插入为:INSERT INTO dept_manager VALUES('d001',10002,'1996-08-03','9999-01-01');INSERT INTO dept_manager VALUES('d002',10006,'1990-08-05','9999-01-01');INSERT INTO dept_manager VALUES('d003',10005,'1989-09-12','9999-01-01');INSERT INTO dept_manager VALUES('d004',10004,'1986-12-01','9999-01-01');INSERT INTO dept_manager VALUES('d005',10010,'1996-11-24','2000-06-26');INSERT INTO dept_manager VALUES('d006',10010,'2000-06-26','9999-01-01');INSERT INTO employees VALUES(10001,'1953-09-02','Georgi','Facello','M','1986-06-26');INSERT INTO employees VALUES(10002,'1964-06-02','Bezalel','Simmel','F','1985-11-21');INSERT INTO employees VALUES(10003,'1959-12-03','Parto','Bamford','M','1986-08-28');INSERT INTO employees VALUES(10004,'1954-05-01','Chirstian','Koblick','M','1986-12-01');INSERT INTO employees VALUES(10005,'1955-01-21','Kyoichi','Maliniak','M','1989-09-12');INSERT INTO employees VALUES(10006,'1953-04-20','Anneke','Preusig','F','1989-06-02');INSERT INTO employees VALUES(10007,'1957-05-23','Tzvetan','Zielinski','F','1989-02-10');INSERT INTO employees VALUES(10008,'1958-02-19','Saniya','Kalloufi','M','1994-09-15');INSERT INTO employees VALUES(10009,'1952-04-19','Sumant','Peac','F','1985-02-18');INSERT INTO employees VALUES(10010,'1963-06-01','Duangkaew','Piveteau','F','1989-08-24');INSERT INTO employees VALUES(10011,'1953-11-07','Mary','Sluis','F','1990-01-22');

解答

• 我的答案

select d.emp_nofrom dept_manager d join employees e on d.emp_no=e.emp_nowhere d.dept_no is null

不通过

• 解答

题目：获取所有非manager的员工的emp_no方法1：NOT IN+子查询select emp_nofrom employeeswhere emp_no not in (select emp_no from dept_manager);尝试：嵌套查询select emp_nofrom employeeswhere emp_no not in (select emp_no from dept_manager)方法2：LEFT JOIN左连接+IS NULLSELECT e.emp_noFROM employees AS eLEFT JOIN dept_manager AS dON e.emp_no=d.emp_noWHERE dept_no IS NULL;尝试：连接查询select e.emp_nofrom employees e left join dept_manager d on e.emp_no=d.emp_nowhere dept_no is null