LeeCode——Combine Two Tables

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

解题思路较为简单，使用left join即可解决.
答案如下图所示：

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

原文地址：https://www.cnblogs.com/jason1990/p/11632524.html