Combine Two Tables SQL Challenge - MySQL Solution

1. Introduction

In this blog post, we will demonstrate how to join data from two MySQL tables. The Person and Address tables serve as our examples, showcasing a practical scenario in database management where related data is merged for comprehensive insights.


Our task is to report the first name, last name, city, and state of each individual in the Person table. If an individual’s address isn’t available in the Address table, null values should be shown for both city and state.

Database Table:

Person Table:
personId lastName firstName
1 Wang Allen
2 Alice Bob
Address Table:
addressId personId city state
1 2 New York City New York

3. MySQL Solution

SELECT p.firstName, p.lastName,, a.state
FROM Person p
LEFT JOIN Address a ON p.personId = a.personId;


Output Table:
firstName lastName city state
Allen Wang Null Null
Bob Alice New York City New York


1. A LEFT JOIN is used to merge the Person and Address tables.

2. The query selects firstName and lastName from Person.

3. city and state are sourced from Address.

4. If there's no corresponding personId in Address, null values are shown for city and state.