光标更新所有行而不是一行

Question

我需要查看一个视图 (vRidesForPricing) 并将每一行与另一个视图 (vRidesDone) 的内容进行比较。

我正在搜索匹配项 - 如果 RidesDone 的当前行的 CompanyID、SourceId 和 DestinationId 与 RidesForPricing 中的这些字段匹配，那么我想用 @ 更新 RidesForPricing 987654329@RidesDone 的值（意思是如果在我只想拿它的价格并复制它之前发生完全相同的骑行）。

我写了一个游标，但它用相同的值更新了RidesForPricing 中的所有行。我错过了什么？任何帮助，将不胜感激。我正在使用 SQL Server 2008 R2。

DECLARE @CompanyID as int, @Date datetime, @SourceId as int, @DestinationId as int, @PriceOffice as nvarchar(250)

DECLARE @RidesForPricingCursor as CURSOR;
SET @RidesForPricingCursor = CURSOR FOR
SELECT CompanyID, Date, SourceId, DestinationId, PriceOffice
FROM dbo.vRidesForPricing
FOR UPDATE OF PriceOffice

OPEN @RidesForPricingCursor;
FETCH NEXT FROM @RidesForPricingCursor 
INTO @CompanyID, @Date, @SourceId, @DestinationId, @PriceOffice

CREATE TABLE #TEMP (CompanyID int, Date datetime, SourceId int, DestinationId int,
            PriceOffice nvarchar(250))

WHILE @@FETCH_STATUS = 0
BEGIN

INSERT INTO #TEMP
SELECT CompanyID, Date, SourceId, DestinationId, PriceOffice
FROM dbo.vRidesDone 
WHERE CompanyID = @CompanyID AND SourceId = @SourceId AND DestinationId = @DestinationId
ORDER BY Date

IF (SELECT COUNT(*) FROM #TEMP) > 0
SET @PriceOffice = (SELECT TOP 1 PriceOffice FROM #TEMP)

UPDATE vRidesForPricing 
SET PriceOffice = @PriceOffice WHERE CURRENT OF @RidesForPricingCursor

FETCH NEXT FROM @RidesForPricingCursor 
INTO @CompanyID, @Date, @SourceId, @DestinationId, @PriceOffice;

END
DROP TABLE #TEMP

CLOSE @RidesForPricingCursor;
DEALLOCATE @RidesForPricingCursor; 

Answer 1

你为什么不只是放下光标（这是一个内存和资源的消耗和主要的性能杀手），只是做一个漂亮的，基于集合的 @ 987654321@:

UPDATE 
    rfp
SET
    PriceOffice = rd.PriceOffice
FROM 
    dbo.vRidesForPricing rfp
INNER JOIN
    dbo.vRidesDone rd ON rfp.CompanyID = rd.CompanyID
                      AND rfp.SourceId = rd.SourceId
                      AND rfp.DestinationId = rd.DestinationId 

这会更新您期望更新的内容吗？