Combine Two Tables --leetcode

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


solution:

普通的LEFT JOIN 關聯
SELECT p.FirstName, p.LastName, a.City, a.State FROM Person p LEFT JOIN Address  a ON p.PersonId = a.PersonId;

們也可使用關鍵Using來聲明咱們相用哪一個列名來進行聯合
SELECT p.FirstName, p.LastName, a.City, a.State FROM Person p LEFT JOIN Address a  using(PersonId);

自動搜索相同的列 nature
SELECT p.FirstName, p.LastName, a.City, a.State FROM Person p NATURAL LEFT JOIN Address  a

git地址：https://github.com/woshiyexinjie/leetcode-xin