SQL动态列和更新多列

时间:2016-11-16 17:07:54

标签: sql sql-server

我有一个表UserPermission,其中包含多个TINYINT类型的列。例如,读,写,更新,删除,访问等。

我在存储过程中得到三个参数:@UserId, @ColNames, @ColValues其中@ColNames@ColValues是逗号分隔值。

如何使用传递的列名和相应的值插入或更新表行(如果已存在)。

我尝试编写适用于INSERT的动态查询,但我无法动态编写UPDATE查询,每列都要连接它的值。

任何回复都将不胜感激

提前致谢。

2 个答案:

答案 0 :(得分:0)

这是一种有点脏的方式来做你需要的。但是,如果您创建以下存储过程:

CREATE FUNCTION [dbo].[stringSplit]
(
    @String NVARCHAR(4000),
    @Delimiter NCHAR(1)
)
RETURNS TABLE
AS
RETURN
(
    WITH Split(stpos,endpos)
    AS(
        SELECT 0 AS stpos, CHARINDEX(@Delimiter,@String) AS endpos
        UNION ALL
        SELECT endpos+1, CHARINDEX(@Delimiter,@String,endpos+1)
            FROM Split
            WHERE endpos > 0
    )
    SELECT 'Id' = ROW_NUMBER() OVER (ORDER BY (SELECT 1)),
        'Data' = SUBSTRING(@String,stpos,COALESCE(NULLIF(endpos,0),LEN(@String)+1)-stpos)
    FROM Split
)

然后,您可以使用该过程将数据连接在一起:

DECLARE @TotalCols INT
DECLARE @TotalVals INT

SET @TotalCols = (
        SELECT COUNT(ID) AS Total
        FROM dbo.stringSplit('department, teamlead', ',')
        );
 SET @TotalVals = (
         SELECT COUNT(ID) AS Total
         FROM dbo.stringSplit('IT, Bob', ',')
         );

 IF @TotalCols = @TotalVals
 BEGIN
     IF OBJECT_ID('tempdb..#temptable') IS NOT NULL
         DROP TABLE #temptable

     CREATE TABLE #temptable (
        ColName VARCHAR(MAX) NULL
        ,ColValue VARCHAR(MAX) NULL
        )

     INSERT INTO #temptable
     SELECT a.DATA
         ,b.DATA
    FROM dbo.stringSplit('department, teamlead', ',') AS a
    INNER JOIN dbo.stringSplit('IT, Bob', ',') AS b ON a.Id = b.Id

    SELECT *
    FROM #temptable;
END

效率不高,但会带来理想的效果。

然后,您可以根据需要使用临时表进行更新,插入和删除。

答案 1 :(得分:0)

我没有逗号分隔列表,而是为每个列创建一个单独的参数,并将其默认值设置为NULL,如果为null或插入0,则代码更新中没有任何内容。像这样....

CREATE PROCEDURE usp_UserPermissions
 @UserID INT 
,@Update INT = NULL  --<-- Make default values NULL
,@Delete INT = NULL
,@Read   INT = NULL
,@Write  INT = NULL
,@Access INT = NULL
AS
BEGIN
  SET NOCOUNT ON;

Declare @t TABLE (UserID INT, [Update] INT,[Read] INT
                 ,[Write] INT,[Delete] INT,[Access] INT)

INSERT INTO @t (Userid, [Update],[Read],[Write],[Delete],[Access])
VALUES (@UserID , @Update , @Read, @Write , @Delete, @Access)   


IF EXISTS (SELECT 1 FROM UserPermission WHERE UserID = @UserID)
  BEGIN 
       UPDATE up        -- Only update if a value was provided else update to itself
        SET up.[Read]   = ISNULL(t.[Read]   , up.[Read])
           ,up.[Write]  = ISNULL(t.[Write]  , up.[Write])
           ,up.[Update] = ISNULL(t.[Update] , up.[Update])
           ,up.[Delete] = ISNULL(t.[Delete] , up.[Delete])
           ,up.[Access] = ISNULL(t.[Access] , up.[Access])
       FROM UserPermission up 
       INNER JOIN @t t ON up.UserID = t.UserID
  END
ELSE 
  BEGIN
         -- if already no row exists for that User add a row 
         -- If no value was passed for a column add 0 as default
    INSERT INTO UserPermission (Userid, [Update],[Read],[Write],[Delete],[Access])
    SELECT Userid
         , ISNULL([Update], 0)
         , ISNULL([Read], 0)
         , ISNULL([Write], 0)
         , ISNULL([Delete], 0)
         , ISNULL([Access], 0)
    FROM @t
  END

END