Co oznacza „ORDER BY (SELECT NULL)”?
Poniższy SQL pochodzi z Itzika Ben-Gana, który służy do generowania tabeli liczb. Co robiorder by (select null)
część znaczy? Dzięki.
<code>DECLARE @number_of_numbers INT; SELECT @number_of_numbers = 100000; WITH a AS ( SELECT 1 AS i UNION ALL SELECT 1 ), b AS ( SELECT 1 AS i FROM a AS x , a AS y ), c AS ( SELECT 1 AS i FROM b AS x , b AS y ), d AS ( SELECT 1 AS i FROM c AS x , c AS y ), e AS ( SELECT 1 AS i FROM d AS x , d AS y ), f AS ( SELECT 1 AS i FROM e AS x , e AS y ), numbers AS ( SELECT TOP ( @number_of_numbers ) ROW_NUMBER() OVER ( ORDER BY ( SELECT NULL ) ) AS number FROM f ) SELECT * FROM numbers; </code>
Dzięki!