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大数据第28天-MySQL练习题1-杨大伟

时间:2020-08-01 00:16:30      阅读:141      评论:0      收藏:0      [点我收藏+]

1. 组合两个表

需求:编写一个 SQL 查询,对两表进行关联,展示列为: FirstName, LastName, City, State

展示效果:

FirstNameLastNameCityState
Allen Wang New York City New York

    

1 Create table Person (PersonId int, FirstName varchar(255), LastName varchar(255));
2 
3 Create table Address (AddressId int, PersonId int, City varchar(255), State varchar(255));
4 
5 insert into Person (PersonId, LastName, FirstName) values (1, Wang, Allen);
6 insert into Address (AddressId, PersonId, City, State) values (1, 1, New York City, New York);

最终SQL:

 1 select
 2      p.FirstName,
 3      p.LastName,
 4      a.City,
 5      a.State
 6 from 
 7      Person as p 
 8 left join 
 9      Address as a 
10 on 
11      p.PersonId = a.PersonId;

 

大数据第28天-MySQL练习题1-杨大伟

原文:https://www.cnblogs.com/shui68home/p/13412858.html

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