Database

175. Combine Two Tables

描述

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

实现

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

分析

Runtime: 927ms

原文地址:https://www.cnblogs.com/hippiebaby/p/5430953.html