The CROSS JOIN joins each row of the first table with each row of
the second table.
In other words, the cross join returns a cartesian product of rows from
both tables.
Unlike INNER JOIN or LEFT JOIN, CROSS JOIN does
not establish a relationship between the joined tables.
Suppose table 1 contains three rows 1, 2 and 3 and table T2 contains
three rows A, B and C.
CROSS JOIN gets a row from the first table (T1) and then creates a
new row for each row from the second table (T2). It then does the same
thing for the next row of the first table (T1) and so on.
MySQL Server CROSS JOIN Examples
The following statement returns the combinations of all Students and
Tests.
SELECT name, note FROM alumni.ma1b02 CROSS JOIN
alumni.evaluations_notes ORDER BY note;
Obtaining the following result:
As can be seen, a Cartesian product of the records in Table1 with the
records in Table2 is obtained.