Generating a sequence in sql server

前端 未结 2 1619
我在风中等你
我在风中等你 2021-01-14 00:18

I am working on a function that will take a low number and a high number as paramaters and returns a table containing everything between (and including).

I know I co

2条回答
  •  自闭症患者
    2021-01-14 00:39

    Just create an indexed permanent auxiliary numbers table and be done with it. This will out perform any other method.

    See Jeff Moden's answer here for more details and a script to populate such a table. if for some reason that isn't an option this should beat the recursive CTE according to the performance tests in the linked answer.

       WITH E00(N) AS (SELECT 1 UNION ALL SELECT 1),
            E02(N) AS (SELECT 1 FROM E00 a, E00 b),
            E04(N) AS (SELECT 1 FROM E02 a, E02 b),
            E08(N) AS (SELECT 1 FROM E04 a, E04 b),
            E16(N) AS (SELECT 1 FROM E08 a, E08 b),
            E32(N) AS (SELECT 1 FROM E16 a, E16 b),
       cteTally(N) AS (SELECT ROW_NUMBER() OVER (ORDER BY N) FROM E32)
       SELECT N FROM cteTally
       WHERE N BETWEEN 10 AND 20
    

提交回复
热议问题