What is the difference between Left Join, Right Join, and Inner Join?

• INNER JOIN: Returns rows where there are matches in both tables.
• LEFT JOIN: Returns all rows from the "left" table and matching rows from the "right" table. If there are no matches in the "right" table, NULLs are returned for columns from the "right" table.
• RIGHT JOIN: Returns all rows from the "right" table and matching rows from the "left" table. If there are no matches in the "left" table, NULLs are returned for columns from the "left" table.

Visualization:

Join Type	Included rows
INNER JOIN	Only matching rows from both tables.
LEFT JOIN	All rows from the left table + matching rows from the right (if any).
RIGHT JOIN	All rows from the right table + matching rows from the left (if any).

SQL example:

-- INNER JOIN
SELECT *
FROM TableA
INNER JOIN TableB ON TableA.ID = TableB.ID;

-- LEFT JOIN
SELECT *
FROM TableA
LEFT JOIN TableB ON TableA.ID = TableB.ID;

-- RIGHT JOIN
SELECT *
FROM TableA
RIGHT JOIN TableB ON TableA.ID = TableB.ID;