| -- |
| -- SELECT_HAVING |
| -- |
| |
| -- load test data |
| CREATE TABLE test_having (a int, b int, c char(8), d char); |
| INSERT INTO test_having VALUES (0, 1, 'XXXX', 'A'); |
| INSERT INTO test_having VALUES (1, 2, 'AAAA', 'b'); |
| INSERT INTO test_having VALUES (2, 2, 'AAAA', 'c'); |
| INSERT INTO test_having VALUES (3, 3, 'BBBB', 'D'); |
| INSERT INTO test_having VALUES (4, 3, 'BBBB', 'e'); |
| INSERT INTO test_having VALUES (5, 3, 'bbbb', 'F'); |
| INSERT INTO test_having VALUES (6, 4, 'cccc', 'g'); |
| INSERT INTO test_having VALUES (7, 4, 'cccc', 'h'); |
| INSERT INTO test_having VALUES (8, 4, 'CCCC', 'I'); |
| INSERT INTO test_having VALUES (9, 4, 'CCCC', 'j'); |
| |
| SELECT b, c FROM test_having |
| GROUP BY b, c HAVING count(*) = 1 ORDER BY b, c; |
| |
| -- HAVING is effectively equivalent to WHERE in this case |
| SELECT b, c FROM test_having |
| GROUP BY b, c HAVING b = 3 ORDER BY b, c; |
| |
| SELECT lower(c), count(c) FROM test_having |
| GROUP BY lower(c) HAVING count(*) > 2 OR min(a) = max(a) |
| ORDER BY lower(c); |
| |
| SELECT c, max(a) FROM test_having |
| GROUP BY c HAVING count(*) > 2 OR min(a) = max(a) |
| ORDER BY c; |
| |
| -- test degenerate cases involving HAVING without GROUP BY |
| -- Per SQL spec, these should generate 0 or 1 row, even without aggregates |
| |
| SELECT min(a), max(a) FROM test_having HAVING min(a) = max(a); |
| SELECT min(a), max(a) FROM test_having HAVING min(a) < max(a); |
| |
| -- errors: ungrouped column references |
| SELECT a FROM test_having HAVING min(a) < max(a); |
| SELECT 1 AS one FROM test_having HAVING a > 1; |
| |
| -- the really degenerate case: need not scan table at all |
| SELECT 1 AS one FROM test_having HAVING 1 > 2; |
| SELECT 1 AS one FROM test_having HAVING 1 < 2; |
| |
| -- and just to prove that we aren't scanning the table: |
| SELECT 1 AS one FROM test_having WHERE 1/a = 1 HAVING 1 < 2; |
| |
| DROP TABLE test_having; |