【MySQL】【leetcode】 Combine Two Tables解题报告

最新推荐文章于 2022-01-29 12:30:00 发布

原创最新推荐文章于 2022-01-29 12:30:00 发布 · 1.6k 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#数据库 #mysql #leetcode

leetcode 专栏收录该内容

38 篇文章

订阅专栏

本文介绍了一个SQL查询案例，通过左外连接实现从Person表中获取每个人的姓名，并从Address表中匹配对应的城市和州信息，即使某些人没有地址记录也能完整列出。

题目

Table: Person

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| PersonId    | int     |
| FirstName   | varchar |
| LastName    | varchar |
+-------------+---------+

PersonId is the primary key column for this table.
Table: Address

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| AddressId   | int     |
| PersonId    | int     |
| City        | varchar |
| State       | varchar |
+-------------+---------+

AddressId is the primary key column for this table.

Write a SQL query for a report that provides the following information for each person in the Person table, regardless if there is an address for each of those people:

FirstName, LastName, City, State

代码

一个左外连接就行了。

# Write your MySQL query statement below
select FirstName, LastName, City, State 
from Person left outer join Address 
on Person.PersonID = Address.PersonID;