[LeetCode](초급) 175.Combine Two Tables

문제

Column Name	Type
personId	int
lastName	varchar
firstName	varchar

[Table : Person]
personId is the primary key (column with unique values) for this table.
This table contains information about the ID of some persons and their first and last names.

 

 

Column Name	Type
addressId	int
personId	int
city	varchar
state	varchar

[Table : Address]
addressId is the primary key (column with unique values) for this table.
Each row of this table contains information about the city and state of one person with ID = PersonId.

 

Write a solution 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.

 

Person 테이블의 각각 사람의 first name, last name, city, state 를 출력해라.

정보가 없다면 null 로 대신 출력해라.

 

풀이

SELECT a.firstName, a.lastName, b.city, b.state
FROM Person a
LEFT OUTER JOIN Address b ON a.personId = b.personId

 

출력결과

firstName	lastName	city	state
Allen	Wang	null	null
Bob	Alice	New York City	New York