中文題目

表1: Person

+-------------+---------+
| 列名 | 類型 |
+-------------+---------+
| PersonId | int |
| FirstName | varchar |
| LastName | varchar |
+-------------+---------+
PersonId 是上表主鍵.
表2: Address

+-------------+---------+
| 列名 | 類型 |
+-------------+---------+
| AddressId | int |
| PersonId | int |
| City | varchar |
| State | varchar |
+-------------+---------+
AddressId 是上表主鍵.

寫一個 SQL 查詢語句，滿足條件：無論 person 是否有地址信息，都需要基于上述兩表提供 person 的以下信息：

FirstName, LastName, City, State

英文題目

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

參考答案

方法一：

SELECT p.FirstName, p.LastName, a.City, a.State FROM Person2 p LEFT JOIN Address a USING (PersonId)

方法二：

SELECT p.FirstName, p.LastName, a.City, a.State FROM Person2 p LEFT JOIN Address a ON(p.PersonId = a.PersonId)

方法三：

SELECT p.FirstName, p.LastName, a.City, a.State FROM Person2 p,Address a WHERE p.PersonId = a.PersonId