SQL CROSS JOIN
SQL CROSS JOIN will return all records where each row from the first table is combined with each row from the second table. Which also mean CROSS JOIN returns the Cartesian product of the sets of rows from the joined tables.
A CROSS JOIN can be specified in two ways: using the JOIN syntax or by listing the tables in the FROM clause separated by commas without using a WHERE clause to supply join criteria.
SQL CROSS JOIN syntax:
SELECT * FROM [TABLE 1] CROSS JOIN [TABLE 2]
OR
SELECT * FROM [TABLE 1], [TABLE 2]
EXAMPLE :
Let's try with 2 tables below:
Table 1: GameScores
| PlayerName | DepartmentId | Scores |
| Jason | 1 | 3000 |
| Irene | 1 | 1500 |
| Jane | 2 | 1000 |
| David | 2 | 2500 |
| Paul | 3 | 2000 |
| James | 3 | 2000 |
Table 2: Departments
| DepartmentId | DepartmentName |
| 1 | IT |
| 2 | Marketing |
| 3 | HR |
SQL statement :
SELECT* FROM GameScores CROSS JOIN Departments
Result:
| PlayerName | DepartmentId | Scores | DepartmentId | DepartmentName |
| Jason | 1 | 3000 | 1 | IT |
| Irene | 1 | 1500 | 1 | IT |
| Jane | 2 | 1000 | 1 | IT |
| David | 2 | 2500 | 1 | IT |
| Paul | 3 | 2000 | 1 | IT |
| James | 3 | 2000 | 1 | IT |
| Jason | 1 | 3000 | 2 | Marketing |
| Irene | 1 | 1500 | 2 | Marketing |
| Jane | 2 | 1000 | 2 | Marketing |
| David | 2 | 2500 | 2 | Marketing |
| Paul | 3 | 2000 | 2 | Marketing |
| James | 3 | 3000 | 2 | Marketing |
| Jason | 1 | 3000 | 3 | HR |
| Irene | 1 | 1500 | 3 | HR |
| Jane | 2 | 1000 | 3 | HR |
| David | 2 | 2500 | 3 | HR |
| Paul | 3 | 2000 | 3 | HR |
| James | 3 | 3000 | 3 | HR |