SQL – Joining two tables without related data – joining without an on clause

I’m loading test data, and have a situation where I have a list of ID’s I need to generate test-data for, and a list of sample data I’d like to populate for each test ID.  Something like this:

TestIDs
———
1
2
3

TestData
——–
A
B

What I want is a join that produces:

Result
——–
1 A
1 B
2 A
2 B
3 A
3 B

This is essentially a join without an “on” clause, however the trick in SQL is that the “join” keyword isn’t needed either.  The select statement is simply:

select * from TestIDs, TestData

Notice that there is a comma seperating the tables to select from, and no join keyword anywhere.  Handy!