What are the types of joins? Write the output of each join.

SQL supports several join types:

1. INNER JOIN – Returns rows that have matching values in both tables. Example: If A has (1,2,3) and B has (2,3,4), the inner join on the key returns (2,3).

1. LEFT (OUTER) JOIN – Returns all rows from the left table and matching rows from the right table; unmatched rows from the right are NULL. Example: A (1,2,3) left join B (2,3,4) yields (1,NULL), (2,2), (3,3).

1. RIGHT (OUTER) JOIN – Symmetric to LEFT JOIN, returning all rows from the right table. Example: A left join B gives (1,NULL),(2,2),(3,3); right join gives (2,2),(3,3),(4,NULL).

1. FULL (OUTER) JOIN – Returns all rows when there is a match in either table; unmatched rows are NULL. Example: A (1,2,3) full join B (2,3,4) yields (1,NULL),(2,2),(3,3),(4,NULL).

1. CROSS JOIN – Produces the Cartesian product of the two tables. Example: A (1,2) cross B (3,4) yields (1,3),(1,4),(2,3),(2,4).

1. SELF JOIN – A table joined to itself, often used to compare rows within the same table. Example: Employees table joined on manager_id to list each employee with their manager.

Each join type serves a specific purpose, and choosing the right one depends on the desired result set and the relationships between the tables.