使用含有关键字exists查找未分配具体部门的员工的所有信息。

SQL251. 使用含有关键字exists查找未分配具体部门的员工的所有信息。

emp_no	birth_date	first_name	last_name	gender	hire_date
10011	1953-11-07	Mary	Sluis	F	1990-01-22

示例1

输入:

drop table if exists employees;
drop table if exists dept_emp;
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`));
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`));
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');
INSERT INTO dept_emp VALUES(10001,'d001','1986-06-26','9999-01-01');
INSERT INTO dept_emp VALUES(10002,'d001','1996-08-03','9999-01-01');
INSERT INTO dept_emp VALUES(10003,'d004','1995-12-03','9999-01-01');
INSERT INTO dept_emp VALUES(10004,'d004','1986-12-01','9999-01-01');
INSERT INTO dept_emp VALUES(10005,'d003','1989-09-12','9999-01-01');
INSERT INTO dept_emp VALUES(10006,'d002','1990-08-05','9999-01-01');
INSERT INTO dept_emp VALUES(10007,'d005','1989-02-10','9999-01-01');
INSERT INTO dept_emp VALUES(10008,'d005','1998-03-11','2000-07-31');
INSERT INTO dept_emp VALUES(10009,'d006','1985-02-18','9999-01-01');
INSERT INTO dept_emp VALUES(10010,'d005','1996-11-24','2000-06-26');
INSERT INTO dept_emp VALUES(10010,'d006','2000-06-26','9999-01-01');

输出:

10011|1953-11-07|Mary|Sluis|F|1990-01-22

原站题解

Sqlite 解法, 执行用时: 10ms, 内存消耗: 3244KB, 提交时间: 2020-11-23

select * 
from employees
where not exists (select emp_no from dept_emp where employees.emp_no = dept_emp.emp_no)

Sqlite 解法, 执行用时: 10ms, 内存消耗: 3260KB, 提交时间: 2021-07-26

select *
from employees e 
where not exists (select * from dept_emp d where e.emp_no=d.emp_no)

Sqlite 解法, 执行用时: 10ms, 内存消耗: 3268KB, 提交时间: 2021-08-07

SELECT *
FROM employees 
WHERE  not EXISTS ( select emp_no from dept_emp where employees.emp_no=dept_emp.emp_no)

Sqlite 解法, 执行用时: 10ms, 内存消耗: 3280KB, 提交时间: 2021-08-07

select * from employees 
where not exists (select emp_no from dept_emp where employees.emp_no = dept_emp.emp_no)

Sqlite 解法, 执行用时: 10ms, 内存消耗: 3284KB, 提交时间: 2020-07-12



SELECT *
FROM employees
WHERE NOT EXISTS (SELECT emp_no FROM dept_emp
WHERE employees.emp_no = dept_emp.emp_no);

详情