LeetCode 175. Combine Two Tables--Database--數據庫題目

LeetCode 175. Combine Two Tables–Database–數據庫題目

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LeetCode題解專欄：LeetCode題解
我做的所有的LeetCode的題目都放在這個專欄裏，大部分題目Java和Python的解法都有。

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題目地址：Combine Two Tables - LeetCode

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Table: Person

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

PersonId is the primary key column for this table.

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Table: Address

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

AddressId is the primary key column for this table.

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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

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題目意思也很簡單,需要注意的是存在表1不存在表2的數據也要有，所以使用left outer join。
sql語句如下：

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