Question

我可以调用未通过存储过程定义的函数吗？

考虑一下我们的存储过程如下：

CREATE PROCEDURE [dbo].[stp__getClients]
AS

BEGIN
    SET NOCOUNT ON;


    Select Id,Name,Status , 
           (CASE WHEN Status = 3 then run_date_calc(FromDate , ToDate) else '' 
            end) as DateRangeDesc
    From ClientsTbl

...
END
GO

我想在Select添加另一个属性：

(CASE WHEN Status = 3 then run_date_calc(FromDate , ToDate) else '' end)

我们想在SP内部创建一个名为run_date_calc的函数将得到两个日期并返回一个包含其范围描述的字符串看起来像：

declare @d1 datetime, @d2 datetime, @year int, @month int, @d int
set @d1 = '2009-09-24'
set @d2 = '2012-04-23'

set @year = datediff(year, @d1, @d2) - 1
set @month = datediff(month, dateadd(year, @year, @d1), @d2) 
if dateadd(month, @month, dateadd(year, @year, @d1)) > @d2 set @month = @month - 1

set @d = datediff(day, dateadd(month, @month, dateadd(year, @year, @d1)), @d2)
print cast(@year as nvarchar) + ' year(s) ' + cast(@month as nvarchar) + ' month(s) and ' + cast(@d as nvarchar) + ' day(s)'

是否可以制作一个＆＃34;内部功能＆＃34;并在SP内部使用它，而不是在DB中创建它？

由于

Answer 1

你不能在SP内“创建”或定义一个函数，没有。您必须在/ a数据库上创建它，然后引用您创建的对象。

如果由于某些奇怪的原因你不希望保留该对象，你可以在TempDB中DROP，使用它，然后/** * Required: set 'ot_theme_mode' filter to true. */ add_filter( 'ot_theme_mode', '__return_true' ); /** * Required: include OptionTree. */ require( trailingslashit( get_template_directory() ) . 'option-tree/ot-loader.php' );它（但是这意味着SP不能同时由两个用户运行，因为该对象已经存在）。

只需永久创建它。

Answer 2

在数据库中创建一个像这样的函数......

CREATE FUNCTION dbo.run_date_calc
(
    @d1 datetime
,   @d2 datetime
)
RETURNS VARCHAR(100)
AS
BEGIN

    Declare @year int, @month int, @d int;

    SET @year = datediff(year, @d1, @d2) - 1
    SET @month = datediff(month, dateadd(year, @year, @d1), @d2) 

    IF dateadd(month, @month, dateadd(year, @year, @d1)) > @d2 set @month = @month - 1

    set @d = datediff(day, dateadd(month, @month, dateadd(year, @year, @d1)), @d2)

    RETURN (  cast(@year  as varchar(10)) + ' year(s) ' 
            + cast(@month as varchar(10)) + ' month(s) and ' 
            + cast(@d     as varchar(10)) + ' day(s)'
            )

END
GO

然后只需从你的proc

调用

CREATE PROCEDURE [dbo].[stp__getClients]
AS

BEGIN
    SET NOCOUNT ON;


    Select Id,Name,Status , 
           (CASE WHEN Status = 3 then dbo.run_date_calc(FromDate , ToDate) else '' 
            end) as DateRangeDesc
    From ClientsTbl

...
END
GO

Answer 3

正如您所知，您无法在SP内定义功能。此外，您的功能不正确。看看我的解决方案：

declare @d1 datetime, @d2 datetime, @year int, @month int, @d int
set @d1 = '2009-09-24'
set @d2 = '2012-04-23'


SET @year = NULLIF(DATEDIFF(year, @d1, @d2), 0)

IF @year IS NOT NULL AND DATEADD(year, @year, @d1) > @d2
    SET @year = NULLIF(@year - 1, 0)

SET @month = NULLIF(DATEDIFF(month, DATEADD(year, ISNULL(@year, 0), @d1), @d2), 0)

IF DATEADD(month, ISNULL(@month, 0), DATEADD(year, ISNULL(@year, 0), @d1)) > @d2 
    set @month = NULLIF(@month - 1, 0)

set @d = DATEDIFF(day, DATEADD(month, ISNULL(@month, 0), DATEADD(year, ISNULL(@year, 0), @d1)), @d2)

SELECT ISNULL(cast(@year as nvarchar) + ' year(s) ', '') + ISNULL(cast(@month as nvarchar) + ' month(s) and ', '') + cast(@d as nvarchar) + ' day(s)'

而不是使用函数你可以使用CASE语句，但在我看来，它看起来很糟糕：

SELECT 
    --Years
    ISNULL(cast(
        CASE WHEN   DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END 
    AS VARCHAR) + ' year(s) ', '')
    --Months
    + ISNULL(cast(

        CASE WHEN DATEADD(month, ISNULL(NULLIF(DATEDIFF(month, DATEADD(year, ISNULL(CASE WHEN   DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END, 0), @d1), @d2), 0), 0), DATEADD(year, ISNULL(CASE WHEN DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END, 0), @d1)) > @d2 
            THEN NULLIF(DATEDIFF(month, DATEADD(year, ISNULL(CASE WHEN  DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END, 0), @d1), @d2) - 1, 0)
            ELSE NULLIF(DATEDIFF(month, DATEADD(year, ISNULL(CASE WHEN  DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END, 0), @d1), @d2), 0)
            END
        AS VARCHAR) + ' month(s) ', '')
    --Days 
     + cast(DATEDIFF(day, DATEADD(month, ISNULL(CASE WHEN DATEADD(month, ISNULL(NULLIF(DATEDIFF(month, DATEADD(year, ISNULL(CASE WHEN   DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END, 0), @d1), @d2), 0), 0), DATEADD(year, ISNULL(CASE WHEN DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END, 0), @d1)) > @d2 
            THEN NULLIF(DATEDIFF(month, DATEADD(year, ISNULL(CASE WHEN  DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END, 0), @d1), @d2) - 1, 0)
            ELSE NULLIF(DATEDIFF(month, DATEADD(year, ISNULL(CASE WHEN  DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END, 0), @d1), @d2), 0)
            END, 0), DATEADD(year, ISNULL(CASE WHEN DATEADD(year, ISNULL(NULLIF(DATEDIFF(year, @d1, @d2), 0), 0), @d1) > @d2 
            THEN NULLIF(DATEDIFF(year, @d1, @d2) - 1, 0)
            ELSE  NULLIF(DATEDIFF(year, @d1, @d2), 0)
            END , 0), @d1)), @d2) as nvarchar) + ' day(s)'

从存储过程调用函数

3 个答案: