SQL

SQL Practical Notes

By Ancheng|2021-01-20T19:23:23-05:00January 20th, 2021|Categories: Technique技术|Tags: Analytical Functions, Partition by, SQL|

MySQL 'group by' together with 'partition by' Online MySQL Database create table Test(cc varchar(25), item varchar(100), num integer); insert into Test(cc, item, num) values('ca', '8.1.4', 11); insert into Test(cc, item, num) values('cn', '8.1.1', 1); insert into Test(cc, item, num) values('cn', '8.1.4', 15); insert into Test(cc, item, num) values('cn', '8.1.3', 5); insert into Test(cc, item, [...]

如何学习SQL

By Ancheng|2018-07-26T21:41:25-04:00July 26th, 2018|Categories: Note笔记|Tags: SQL|

如何学习 SQL 语言？ - 知乎经典SQL练习题 - CSDN博客 sql练习网站 - CSDN博客 MySQL SQL常用语句自我测试练习-苦逼程序员-迈进-51CTO博客将MySQL安装到D盘 – 程泽群的博客 MySQL Commands sql 练习(五) - 简书经典SQL练习题查询Score表中的最高分的学生学号和课程号。（子查询或者排序） SELECT sno,cno FROM score WHERE degree =(SELECT MAX(degree) FROM score) select sno, cno from score order by degree desc limit 1,1; 查询Score表中至少有5名学生选修的并以3开头的课程的平均分数。 SELECT AVG(degree),cno FROM score WHERE cno LIKE '3%' GROUP BY [...]

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SQL Coding Challenge – Leetcode

By Ancheng|2018-07-26T21:39:33-04:00July 26th, 2018|Categories: Note笔记|Tags: Coding Challenge, leetcode, SQL|

Easy Difficulty Combine Two Tables - LeetCode SELECT FirstName, LastName, City, State FROM Person LEFT JOIN Address ON Person.PersonId = Address.PersonId; Second Highest Salary - LeetCode SELECT distinct(Salary) AS SecondHighestSalary FROM Employee UNION SELECT NULL ORDER BY SecondHighestSalary DESC LIMIT 1, 1; Employee Earning More Than Their Managers Assign two different names for single table and [...]

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