[TIL] SQL join có cả cross join

$ sqlite3
SQLite version 3.37.2 2022-01-06 13:25:41
Enter ".help" for usage hints.
Connected to a transient in-memory database.
Use ".open FILENAME" to reopen on a persistent database.
sqlite> -- Create temporary tables for our sets
WITH set1 AS (
  SELECT 1 AS a UNION ALL
  SELECT 2 UNION ALL
  SELECT 3
),
set2 AS (
  SELECT 4 AS b UNION ALL
  SELECT 5 UNION ALL
  SELECT 6
)

-- Perform cross join to create Cartesian product
SELECT set1.a, set2.b
FROM set1
CROSS JOIN set2
ORDER BY set1.a, set2.b;
1|4
1|5
1|6
2|4
2|5
2|6
3|4
3|5
3|6