SQL JOINS

Join is used to retrieve data from multiple tables. For example, if there are two tables, order and customer, and we want to retrieve data, it is possible using the JOIN clause.

The different types of JOIN are as follows:

• INNER JOIN: Returns only those records which have matching values in both tables.
• CROSS JOIN: Returns only those records which are have matching values in either the left or right table.
• LEFT JOIN: This will returns all records from the left table and only matching records from the right table.
• RIGHT JOIN: This will returns all records from the right table and only matching records from the left table.

The following figure illustrates the example that we looked at briefly: