SQL CROSS JOIN: How to Use Cartesian Product

In SQL, a CROSS JOIN is an operation used to return the Cartesian product between two tables, meaning it will return all possible combinations of the two tables.

For example, suppose there are two tables A and B. Table A has 3 rows of records and table B has 2 rows of records. When using a CROSS JOIN operation, the result set will return 6 rows of records, containing all possible combinations of records from tables A and B.

The syntax for a CROSS JOIN is as follows:

SELECT * 
FROM table1
CROSS JOIN table2;

It is important to note that CROSS JOIN can generate very large result sets, especially when dealing with large tables, which may lead to performance issues. Therefore, it is usually recommended to consider if there is a better alternative before using CROSS JOIN.