Question

我正试图改变下面的观点：

ALTER VIEW [dbo].[Win.v_TodayMin365]
AS

    declare @tblOut table(Dates Date)
    declare @cnt INT = -365
    while @cnt < 0
    Begin
            set @cnt = @cnt + 1;
            insert into @tblOut (Dates) values(cast(dateadd(day,@cnt,getdate()) as Date))
    END
    select * from @tblOut
    deallocate @tblOut
    deallocate @cnt
GO

这样的代码工作（如果我突出显示AS和GO之间的所有内容并点击Execute，我得到预期的输出），但我无法将其作为ALTER VIEW运行。然后，我收到以下错误：

关键字'declare'附近的语法不正确。期待'（'，SELECT或WITH

提前感谢任何想法！

Answer 1

Declare

中的变量不能View

实际上，您不需要使用While循环。使用计数表技巧生成比while循环方法

更有效的日期

ALTER VIEW [dbo].[Win.v_TodayMin365]
AS
  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), --10E+1 or 10 rows
       E2(N)
       AS (SELECT 1 FROM E1 a,E1 b), --10E+2 or 100 rows
       E4(N)
       AS (SELECT 1 FROM E2 a,E2 b), --10E+4 or 10,000 rows max
       calendar
       AS (SELECT Dateadd(dd, Row_number()OVER(ORDER BY n), Dateadd(yy, -1, Cast(Getdate() + 1 AS DATE))) AS dates
           FROM   E4 l)
  SELECT *
  FROM   calendar
  WHERE  dates <= Cast(Getdate() AS DATE)

这甚至可以转换为Table valued function或Stored Procedure。

SQL无法更改具有DECLARE语句的视图

1 个答案: