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175. 组合两个表

175. 组合两个表

地址:https://leetcode-cn.com/problems/combine-two-tables/

//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
// 
// 👍 729 👎 0

MySql解题 Left Join 左连接

# Write your MySQL query statement below
select FirstName, LastName, City, State
from Person t1
left join Address t2 on t1.PersonId = t2.PersonId

完!

posted @ 2021-01-03 13:38  sstu  阅读(67)  评论(0编辑  收藏  举报