本文主要是介绍[SQL] LeetCode 175. 组合两个表 - [Easy],希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!
175. 组合两个表
题目:
表1: Person
+-------------+---------+
| 列名 | 类型 |
+-------------+---------+
| PersonId | int |
| FirstName | varchar |
| LastName | varchar |
+-------------+---------+
- PersonId 是上表主键
表2: Address
+-------------+---------+
| 列名 | 类型 |
+-------------+---------+
| AddressId | int |
| PersonId | int |
| City | varchar |
| State | varchar |
+-------------+---------+
- AddressId 是上表主键
编写一个 SQL 查询,满足条件:无论 person 是否有地址信息,都需要基于上述两表提供 person 的以下信息:
FirstName, LastName, City, State
SQL架构:
Create table Person (PersonId int, FirstName varchar(255), LastName varchar(255));
Create table Address (AddressId int, PersonId int, City varchar(255), State varchar(255));
Truncate table Person;
insert into Person (PersonId, LastName, FirstName) values ('1', 'Wang', 'Allen');
Truncate table Address;
insert into Address (AddressId, PersonId, City, State) values ('1', '2', 'New York City', 'New York');
解题语句:
SELECTp.FirstName, p.LastName, a.City, a.State
FROMPerson AS pLEFT JOIN Address AS a ON p.PersonId = a.PersonId;
这篇关于[SQL] LeetCode 175. 组合两个表 - [Easy]的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!