0175. Combine Two Tables

https://leetcode.com/problems/combine-two-tables

Description

Table: Person

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| PersonId    | int     |
| FirstName   | varchar |
| LastName    | varchar |
+-------------+---------+
PersonId is the primary key column for this table.
This table contains information about the ID of some persons and their first and last names.

Table: Address

+-------------+---------+
| Column Name | Type    |
+-------------+---------+
| AddressId   | int     |
| PersonId    | int     |
| City        | varchar |
| State       | varchar |
+-------------+---------+
AddressId is the primary key column for this table.
Each row of this table containts information about the city and state of one person with ID = PersonId.

Write an SQL query to report the first name, last name, city, and state of each person in the Person table. If the address of a PersonId is not present in the Address table, report null instead.

Return the result table in any order.

The query result format is in the following example.

Example 1:

**Input:** 
Person table:
+----------+----------+-----------+
| PersonId | LastName | FirstName |
+----------+----------+-----------+
| 1        | Wang     | Allen     |
| 2        | Alice    | Bob       |
+----------+----------+-----------+
Address table:
+-----------+----------+---------------+------------+
| AddressId | PersonId | City          | State      |
+-----------+----------+---------------+------------+
| 1         | 2        | New York City | New York   |
| 2         | 3        | Leetcode      | California |
+-----------+----------+---------------+------------+
**Output:** 
+-----------+----------+---------------+----------+
| FirstName | LastName | City          | State    |
+-----------+----------+---------------+----------+
| Allen     | Wang     | Null          | Null     |
| Bob       | Alice    | New York City | New York |
+-----------+----------+---------------+----------+
**Explanation:** 
There is no address in the address table for the PersonId = 1 so we return null in their city and state.
AddressId = 1 contains information about the address of PersonId = 2.

ac

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