ICode9

精准搜索请尝试: 精确搜索
首页 > 数据库> 文章详细

牛客网SQLite笔记

2021-07-03 23:03:04  阅读:235  来源: 互联网

标签:INSERT SQLite 01 employees 笔记 牛客 VALUES date INTO


SQL1 查找最晚入职员工的所有信息

描述

有一个员工employees表简况如下:

img

请你查找employees里最晚入职员工的所有信息,以上例子输出如下:img

示例1

输入:

drop table if exists  `employees` ; 
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`));
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');

输出:

10008|1958-02-19|Saniya|Kalloufi|M|1994-09-15

答题

select * from employees
where hire_date =
(select max(hire_date) from employees)

由于最晚入职的可能不止一个,因此筛选最大的hire_date进行查找

SQL2 查找入职员工时间排名倒数第三的员工所有信息

描述

有一个员工employees表简况如下:

img

请你查找employees里入职员工时间排名倒数第三的员工所有信息,以上例子输出如下:

img

示例1

输入:

drop table if exists  `employees` ; 
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`));
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');

输出:

10005|1955-01-21|Kyoichi|Maliniak|M|1989-09-12

答题

select * from employees order by hire_date desc limit 2,1;

考虑到入职日期可能会有多个重复,最合理的SQL语句应为:

SELECT * FROM employees 
WHERE hire_date = (
SELECT DISTINCT hire_date FROM employees 
ORDER BY hire_date DESC limit 2,1
);

关键词 distinct用于返回唯一不同的值。

SQL3 查找当前薪水详情以及部门编号dept_no

描述

有一个全部员工的薪水表salaries简况如下:

img

有一个各个部门的领导表dept_manager简况如下:

img

请你查找各个部门当前领导的薪水详情以及其对应部门编号dept_no,输出结果以salaries.emp_no升序排序,并且请注意输出结果里面dept_no列是最后一列,以上例子输出如下:

img

示例1

输入:

drop table if exists  `salaries` ; 
drop table if exists  `dept_manager` ; 
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`));
CREATE TABLE `dept_manager` (
`dept_no` char(4) NOT NULL,
`emp_no` int(11) NOT NULL,
`to_date` date NOT NULL,
PRIMARY KEY (`emp_no`,`dept_no`));
INSERT INTO dept_manager VALUES('d001',10002,'9999-01-01');
INSERT INTO dept_manager VALUES('d002',10006,'9999-01-01');
INSERT INTO dept_manager VALUES('d003',10005,'9999-01-01');
INSERT INTO dept_manager VALUES('d004',10004,'9999-01-01');
INSERT INTO salaries VALUES(10001,88958,'2002-06-22','9999-01-01');
INSERT INTO salaries VALUES(10002,72527,'2001-08-02','9999-01-01');
INSERT INTO salaries VALUES(10003,43311,'2001-12-01','9999-01-01');
INSERT INTO salaries VALUES(10004,74057,'2001-11-27','9999-01-01');
INSERT INTO salaries VALUES(10005,94692,'2001-09-09','9999-01-01');
INSERT INTO salaries VALUES(10006,43311,'2001-08-02','9999-01-01');
INSERT INTO salaries VALUES(10007,88070,'2002-02-07','9999-01-01');

复制

输出:

10002|72527|2001-08-02|9999-01-01|d001
10004|74057|2001-11-27|9999-01-01|d004
10005|94692|2001-09-09|9999-01-01|d003
10006|43311|2001-08-02|9999-01-01|d002

答题

select salaries.*,dept_manager.dept_no
from salaries,dept_manager
where
salaries.emp_no = dept_manager.emp_no
and salaries.to_date = '9999-01-01'
and dept_manager.to_date = '9999-01-01'
order by salaries.emp_no 

标签:INSERT,SQLite,01,employees,笔记,牛客,VALUES,date,INTO
来源: https://www.cnblogs.com/dapenson/p/sql-learning.html

本站声明: 1. iCode9 技术分享网(下文简称本站)提供的所有内容,仅供技术学习、探讨和分享;
2. 关于本站的所有留言、评论、转载及引用,纯属内容发起人的个人观点,与本站观点和立场无关;
3. 关于本站的所有言论和文字,纯属内容发起人的个人观点,与本站观点和立场无关;
4. 本站文章均是网友提供,不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属;如您发现该文章侵犯了您的权益,可联系我们第一时间进行删除;
5. 本站为非盈利性的个人网站,所有内容不会用来进行牟利,也不会利用任何形式的广告来间接获益,纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。

专注分享技术,共同学习,共同进步。侵权联系[81616952@qq.com]

Copyright (C)ICode9.com, All Rights Reserved.

ICode9版权所有