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SQL10:获取所有非manager的员工emp_no

程序员文章站 2024-03-22 11:54:58
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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’);
SQL10:获取所有非manager的员工emp_no

方法一:使用NOT IN选出在employees但不在dept_manager中的emp_no记录

SELECT emp_no FROM employees
WHERE emp_no NOT IN (SELECT emp_no FROM dept_manager)

方法二:先使用LEFT JOIN连接两张表,再从此表中选出dept_no值为NULL对应的emp_no记录

SELECT emp_no FROM (SELECT * FROM employees LEFT JOIN dept_manager
ON employees.emp_no = dept_manager.emp_no)
WHERE dept_no IS NULL

方法三:方法二的简版,使用单层SELECT语句即可

SELECT employees.emp_no FROM employees LEFT JOIN dept_manager
ON employees.emp_no = dept_manager.emp_no
WHERE dept_no IS NULL

相关标签: SQL练习 sql