Tell me, what types of JOIN are there.

In SQL, there are several main types of JOINs that allow you to combine data from two or more tables based on a specific condition:

• INNER JOIN — returns only the rows where there are matches in both tables.
• LEFT JOIN (LEFT OUTER JOIN) — returns all rows from the left table and the matching rows from the right table. If there are no matches, the columns from the right table will contain NULL.
• RIGHT JOIN (RIGHT OUTER JOIN) — returns all rows from the right table and the matching rows from the left table.
• FULL JOIN (FULL OUTER JOIN) — returns all rows from both tables, filling with NULL where there are no matches.
• CROSS JOIN — the Cartesian product of two tables, returning all possible combinations of rows.

Example of INNER JOIN:

SELECT users.name, orders.id
FROM users
INNER JOIN orders ON users.id = orders.user_id;

This query will return the names of users and their orders only if the user has orders.