BigQuery full join two tables without a column to join on - google-bigquery

Question

I have two tables:
t1
col1 col2
a a
a c
b a
b d
c a
c d
t2
team game
mazs 1
mazs 2
doos 1
bahs 3
...
t2 is a very long table with many teams and games, whereas t1 is shown in its entirety - a table with 6 rows, featuring combinations of the letters a,b,c,d. Note that t1 is not a fully exhaustive list of a,b,c,d pairings, only the pairings in the 6 rows that appear.
I'd like to create a table that looks like this:
output
team game col1 col2
mazs 1 a a
mazs 1 a c
mazs 1 b a
mazs 1 b d
mazs 1 c a
mazs 1 c d
mazs 2 a a
mazs 2 a c
mazs 2 b a
mazs 2 b d
mazs 2 c a
mazs 2 c d
What's going on here is that for each row in t2, there are 6 rows in output, one row for each of the col1, col2 pairings from t1.
t1 and t2 are created on my end from the following queries:
SELECT col1, col2 FROM sometable GROUP BY col1, col2
SELECT DISTINCT team, game FROM anothertable
The first query creates t1 and the second query creates t2.

Answer 1

It is called CROSS JOIN, see below example:
With t1 as (
select 'a' col1, 'a' col2 union all
select 'a' col1, 'c' col2 union all
select 'b' col1, 'a' col2 union all
select 'b' col1, 'd' col2 union all
select 'c' col1, 'a' col2 union all
select 'c' col1, 'd' col2),
t2 as (
select 'mazs' team, 1 game union all
select 'mazs' team, 2 game union all
select 'doos' team, 1 game union all
select 'bahs' team, 3 game
)
SELECT * FROM t2 cross join t1;
Output:
+------+------+------+------+
| team | game | col1 | col2 |
+------+------+------+------+
| mazs | 1 | a | a |
| mazs | 1 | a | c |
| mazs | 1 | b | a |
| mazs | 1 | b | d |
| mazs | 1 | c | a |
| mazs | 1 | c | d |
| mazs | 2 | a | a |
| mazs | 2 | a | c |
| mazs | 2 | b | a |
| mazs | 2 | b | d |
| mazs | 2 | c | a |
| mazs | 2 | c | d |
| doos | 1 | a | a |
| doos | 1 | a | c |
| doos | 1 | b | a |
| doos | 1 | b | d |
| doos | 1 | c | a |
| doos | 1 | c | d |
| bahs | 3 | a | a |
| bahs | 3 | a | c |
| bahs | 3 | b | a |
| bahs | 3 | b | d |
| bahs | 3 | c | a |
| bahs | 3 | c | d |
+------+------+------+------+