力扣sql题

Posted 2022-02-21 q1359720840

组合两个表

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：

 建表语句：

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‘)

　　解法：

select FirstName, LastName, City, State
from Person left join Address
on Person.PersonId = Address.PersonId

　　

FirstName, LastName, City, State

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/combine-two-tables
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