MySQL LEFT JOIN

What is a LEFT JOIN in MySQL?

A LEFT JOIN in MySQL is a type of join that returns all records from the left table and the matched records from the right table. If there are no matches, the result is NULL for columns from the right table. This join is also known as a Left Outer Join.

How does LEFT JOIN differ from INNER JOIN?

A LEFT JOIN returns all records from the left table and the matched records from the right table, with NULLs for non-matching rows in the right table. An INNER JOIN, on the other hand, returns only the records that have matching values in both tables.

Can I use a WHERE clause with a LEFT JOIN?

Yes, you can use a WHERE clause with a LEFT JOIN to filter the results. However, be cautious: filtering on columns from the right table can effectively turn the LEFT JOIN into an INNER JOIN if the filter excludes NULLs. To avoid this, ensure the filter conditions are designed to retain the desired

In databases, data is often stored in multiple tables, making it necessary to combine them to fetch required information. MySQL JOIN statements enable merging tables based on common columns.

In this article, we’ll explore the MySQL LEFT JOIN keyword, a type of outer join that returns all records from the left table and matched records from the right table. We’ll cover its syntax, examples, and use cases to understand its functionality better.