What is the difference between using LEFT JOIN and RIGHT JOIN when joining tables in SQL?

LEFT JOIN and RIGHT JOIN are types of table joins in SQL that differ in the direction of row inclusion:

• LEFT JOIN returns all rows from the left table and the matching rows from the right table. If there are no matches in the right table, the right table fields will be NULL.
• RIGHT JOIN returns all rows from the right table and the matching rows from the left table. If there are no matches in the left table, the left table fields will be NULL.

Example:

SELECT a.id, b.value
FROM tableA a
LEFT JOIN tableB b ON a.id = b.a_id;

This query will return all records from tableA, even if there are no matches in tableB.

If you replace LEFT JOIN with RIGHT JOIN, all records from tableB with matches from tableA will be returned.

Essentially, LEFT JOIN and RIGHT JOIN are mirror images of each other, and one can be rewritten using the other by changing the order of the tables.