How do SQL Joins Work?

The diagram above shows how 4 types of SQL joins work in detail.

INNER JOIN

Returns matching rows in both tables.

LEFT JOIN

Returns all records from the left table, and the matching records from the right table.

RIGHT JOIN

Returns all records from the right table, and the matching records from the left table.

FULL OUTER JOIN

Returns all records where there is a match in either left or right table.