What types of table joins have you used in your SQL queries?

Various types of table joins (JOIN) are used in SQL queries to combine data from multiple tables:

• INNER JOIN — returns rows with matches in both tables.
• LEFT JOIN (LEFT OUTER JOIN) — returns all rows from the left table and matching rows from the right; if no match, NULLs are used.
• RIGHT JOIN (RIGHT OUTER JOIN) — the opposite, all from the right and matching from the left.
• FULL JOIN (FULL OUTER JOIN) — returns all rows from both tables, filling NULLs where there are no matches.
• CROSS JOIN — Cartesian product, all possible combinations of rows.

Example of INNER JOIN:

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

This query will return the names of users and their order amounts, only for users who have orders.