spróbować czegoś jak:
SELECT 1 AS Val FROM dual
UNION ALL SELECT 2 FROM dual
UNION ALL SELECT 3 FROM dual
UNION ALL SELECT 4 FROM dual
UNION ALL SELECT 5 FROM dual
UNION ALL SELECT 6 FROM dual
UNION ALL SELECT 7 FROM dual;
Jest brudny, ale będzie to rade.
Zmieniano: Ach - trzeba przekazać w zmiennej poinformować, jak wysoko się udać ...
Tak jak o czymś takim:
SELECT t1.Val + t2.Val * 2 + t3.Val * 4 + t4.Val * 8 AS Val
FROM
(
SELECT 0 AS Val FROM dual
UNION ALL SELECT 1 FROM dual
) AS t1,
(
SELECT 0 AS Val FROM dual
UNION ALL SELECT 1 FROM dual
) AS t2,
(
SELECT 0 AS Val FROM dual
UNION ALL SELECT 1 FROM dual
) AS t3,
(
SELECT 0 AS Val FROM dual
UNION ALL SELECT 1 FROM dual
) AS t4
WHERE t1.Val + t2.Val * 2 + t3.Val * 4 + t4.Val * 8 <= 7;
Ok ... edycji ponownie, teraz przy użyciu WITH:
WiTH
A0 AS (SELECT 0 as N FROM DUAL UNION ALL SELECT 0 FROM DUAL),
A1 AS (SELECT 0 as N FROM A0, A0 AS B),
A2 AS (SELECT 0 as N FROM A1, A1 AS B),
A3 AS (SELECT 0 as N FROM A2, A2 AS B),
A4 AS (SELECT 0 as N FROM A3, A3 AS B),
A5 AS (SELECT 0 as N FROM A4, A4 AS B),
A6 AS (SELECT 0 as N FROM A5, A5 AS B),
Nums AS (SELECT ROW_NUMBER() OVER (ORDER BY N) AS Val FROM A6)
SELECT *
FROM Nums
WHERE Val <= :NUM
;
retagged jako wyrocznia, mam nadzieję, że to było poprawne –
@Rob: Postgres obsługuje również PLSQL, ale nie obsługuje 'FROM DUAL', więc Oracle jest poprawne. –
Dzięki Rob, poprawne to pytanie dotyczyło tylko bazy danych Oracle DB – Harish