Question

我希望在数据库中有一个带有整数（1,2，...）的单列的表，因为它对某些连接很有帮助。

我想出了一个使用循环的解决方案。有没有更有效的方法来创建这样的表？

我的解决方案

CREATE TABLE #NUM
(
  NUM int
)

DECLARE @i int=1
WHILE @i<10000
BEGIN
  INSERT INTO #Temp
  SELECT @i 
  SET @i = @i + 1
END

Answer 1

我将使用计数表

来完成此操作

    ;WITH e1(n) AS
(
    SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
    SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL 
    SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1 UNION ALL SELECT 1
), -- 10
e2(n) AS (SELECT 1 FROM e1 CROSS JOIN e1 AS b), -- 10*10
e3(n) AS (SELECT 1 FROM e2 CROSS JOIN e2 AS b) -- 100*100
INSERT INTO #Temp
SELECT  ROW_NUMBER() OVER (ORDER BY n) FROM e3 ORDER BY n;

检查here了解更多信息

Answer 2

这与NoDisplayName的答案原理相同，但我认为它有点清洁（我的观点）：

;WITH TBL(ROW_NUM) AS (
    SELECT 1 AS ROW_NUM
    UNION ALL
    SELECT ROW_NUM+1
    FROM TBL
    WHERE ROW_NUM < 100
)

SELECT ROW_NUMBER() OVER (ORDER BY T1.ROW_NUM) AS ROW_NUM
FROM TBL T1
JOIN TBL T2 ON 1=1
JOIN TBL T3 ON 1=1

Answer 3

SELECT 
row_number() over (order by message_id) num
into #Table
from sys.messages

SQL使用整数创建表

3 个答案: