What are the types of JOIN?

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

• INNER JOIN — returns only the rows that match the condition in both tables.
• LEFT JOIN (LEFT OUTER JOIN) — returns all rows from the left table and the matching rows from the right; if there are no matches, NULLs will appear in the right table's columns.
• RIGHT JOIN (RIGHT OUTER JOIN) — similar to LEFT JOIN, but returns all rows from the right table.
• FULL JOIN (FULL OUTER JOIN) — returns all rows from both tables, filling in NULLs where there are no matches.
• CROSS JOIN — the Cartesian product of two tables, returning all possible combinations of rows.

Example of INNER JOIN:

SELECT employees.name, departments.name
FROM employees
INNER JOIN departments ON employees.department_id = departments.id;