我在询问 b4 关于交换查询以在同一个表中的行之间交换数据,我得到了那个查询
ALTER PROCEDURE [dbo].[VehicleReservationsSwap]
(@FirstVehicleID int,
@secondVehicleID int,
@WhereClause nvarchar(2000))
AS
BEGIN
Create Table #Temp (VehicleID int,
VehicleType nvarchar(100),
JoinId int)
DECLARE @SQL varchar(8000)
SET @SQL = 'Insert into #Temp (VehicleID, VehicleType, JoinId) SELECT
VehicleID,VehicleType,CASE WHEN VehicleID = ' + Cast(@FirstVehicleID as varchar(10)) + ' then ' + Cast(@secondVehicleID as varchar(10)) + ' ELSE ' + Cast(@FirstVehicleID as varchar(10)) + ' END AS JoinId
FROM Reservations
WHERE VehicleID in ( ' + Cast(@FirstVehicleID as varchar(10)) + ' , ' + Cast(@secondVehicleID as varchar(10)) + ' )' + @WhereClause
EXEC(@SQL)
--swap values
UPDATE y
SET y.VehicleID = #Temp.VehicleID,
y.VehicleType = #Temp.VehicleType
FROM Reservations y
INNER JOIN #Temp ON y.VehicleID = #Temp.JoinId
WHERE y.VehicleID in (@FirstVehicleID, @SecondVehicleID)
Drop Table #Temp
END
此查询采用 2 个参数并交换为每个参数返回的所有行。
问题是查询交换,只要每个参数(外键)都有我需要进行交换的值,以防其中一个参数没有值。
我希望有人可以帮助我。
谢谢,