Which types of joins are commonly used in SQL?

The types of joins that are commonly used in SQL are indeed INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL OUTER JOIN. Each of these joins serves a fundamental role in querying relational databases.

An INNER JOIN retrieves records that have matching values in both tables involved in the join. This is useful for returning only the data that is relevant across the tables.

A LEFT JOIN (also known as LEFT OUTER JOIN) returns all records from the left table and the matched records from the right table. If there is no match, NULL values are returned for columns from the right table, allowing retrieval of all records from one side while including any related data from the other.

A RIGHT JOIN (or RIGHT OUTER JOIN) operates similarly but returns all records from the right table and the matched records from the left. This join emphasizes the data available in the right-hand table.

A FULL OUTER JOIN combines the results of both LEFT and RIGHT JOINs, returning all records when there is a match in either left or right table records. It ensures that any data from both sides is included, regardless of whether they match.

These types of joins are fundamental for querying complex datasets where relationships exist between multiple tables, enabling users to extract meaningful information from their