在SQL Server函數中更新

我有一個SQL Server函數從表中獲取下一個ID。這足夠直接，但我也想更新表中所用的ID。我正在使用該技術更新到表格中，但更新沒有發生。代碼如下所示，任何人都知道爲什麼？在SQL Server函數中更新

CREATE FUNCTION [dbo].[GetNextKeyID] 
(
@user nvarchar(10), 
@keytype nvarchar(20) 
) 
RETURNS nvarchar(15) 
AS 
BEGIN 
    DECLARE @NextID nvarchar(15); 

    -- get the next id for this keytype 
    SELECT @NextID = @user + '_' + @keytype + '_' + CONVERT(VARCHAR(3), 
                  (SELECT CASE WHEN @keytype = 'sess' THEN SessionNext 
                     WHEN @keytype = 'event' THEN EventNext 
                     WHEN @keytype = 'evtc' THEN EventConsultantNext 
                     WHEN @keytype = 'act' THEN ActivityNext 
                    END) 
                  ) 
    FROM dbo.[BARKeys] 
    WHERE [UserID] = @user 

    -- increment the next id for this keytype 
    DECLARE @BARKeys TABLE 
    (
     UserID nvarchar(10), 
     SessionNext int, 
     EventNext int, 
     EventConsultantNext int, 
     ActivityNext int 
    ) 

    UPDATE @BARKeys 
    SET SessionNext   = CASE WHEN @keytype ='sess' OR @keytype = 'All' 
            THEN SessionNext + 1 
            ELSE SessionNext END 
     ,EventNext   = CASE WHEN @keytype ='event' OR @keytype = 'All' 
            THEN EventNext + 1 
            ELSE EventNext END 
     ,EventConsultantNext = CASE WHEN @keytype ='evtc' OR @keytype = 'All' 
            THEN EventConsultantNext + 1 
            ELSE EventConsultantNext END 
     ,ActivityNext  = CASE WHEN @keytype ='act' OR @keytype = 'All' 
            THEN ActivityNext + 1 
            ELSE ActivityNext END 
    WHERE [UserID] = @user 

    -- return the next id 
    RETURN @NextID ; 
END

來源

2013-08-26 Bob Phillips