[SQL]组合两个表解题思路

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

1.解题

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

来源:力扣(LeetCode)

 

posted @ 2022-03-16 18:16  未来a  阅读(48)  评论(0)    收藏  举报