【Leetcode】Combine Two Tables

题目链接：https://leetcode.com/problems/combine-two-tables/

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

思路：
考察join语句
inner join是两表交集
outer join是两表除了交集之外的部分，left是不管左边表满不满足on的条件都在结果中，right同理，full是两表并集

算法：

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