The following are functionally equivalent:

SELECT * 
FROM table1, table2

SELECT * 
FROM table1
CROSS JOIN table2

Both perform a cross join, cartesian product.

The second format using the explicit JOIN syntax has been the prefered way of doing a cross join since a long time now.

Reference:

• Stack Overflow https://stackoverflow.com/questions/53583412/what-is-the-difference-between-cross-join-and-multiple-tables-in-one-from

#convention #code