Multi identifier error in trigger function - sql-server

Question

I have a trigger function that create for inserted. I have two stockTransaction and StokItem in the code I wanted to display the changes on StockItem and I succeeded it. But now I simply change the column BuyinPrice of my Item table which is third table after updating StokItem table.
Here is my code:
ALTER TRIGGER [dbo].[StockTransactionInserted]
ON [dbo].[StockTransaction]
AFTER INSERT
AS
BEGIN
SET NOCOUNT ON;
DECLARE
#IdItem int,
#IdStorage int,
#TransactionType char(1),
#Code char(1),
#Quantity decimal(18, 8),
#UnitPrice decimal(18, 8),
#Discount decimal(18, 8),
#FatAltDiscount decimal(18, 8),
#VAT decimal(18, 8)
SELECT
#IdItem = IdItem,
#IdStorage = IdStorage,
#TransactionType = TransactionType,
#Code = Code,
#Quantity = Quantity,
#UnitPrice = UnitPrice,
#Discount = Discount,
#FatAltDiscount = FatAltDiscount,
#VAT = VAT
FROM inserted
IF NOT EXISTS (SELECT * FROM StockItem WHERE IdItem = #IdItem AND IdStorage = #IdStorage)
BEGIN
INSERT INTO StockItem (IdItem, IdStorage, TOP_GIRIS_MIK, TOP_CIKIS_MIK)
VALUES (#IdItem, #IdStorage, 0, 0)
END
UPDATE StockItem
SET
TOP_GIRIS_MIK = TOP_GIRIS_MIK + CASE WHEN #Code = 'G' THEN #Quantity ELSE 0 END,
TOP_GIRIS_TUT = TOP_GIRIS_TUT + CASE WHEN #Code = 'G' THEN (#UnitPrice * (1- #Discount/100)) * #Quantity ELSE 0 END,
TOP_CIKIS_MIK = TOP_CIKIS_MIK + CASE WHEN #Code = 'C' THEN #Quantity ELSE 0 END,
TOP_CIKIS_TUT = TOP_CIKIS_TUT + CASE WHEN #Code = 'C' THEN (#UnitPrice * (1- #Discount/100)) * #Quantity ELSE 0 END,
ORT_BR_FIAT = CASE WHEN ((TOP_GIRIS_MIK - TOP_CIKIS_MIK) + #Quantity) = 0 THEN (ORT_BR_FIAT + (#UnitPrice * (1- #Discount/100))) / 2 ELSE ((TOP_GIRIS_MIK - TOP_CIKIS_MIK) * ORT_BR_FIAT + (#Quantity * (#UnitPrice * (1- #Discount/100)))) / ((TOP_GIRIS_MIK - TOP_CIKIS_MIK) + #Quantity) END,
SON_GIR_BR_FIAT = (CASE WHEN #UnitPrice=0 OR #TransactionType != 'A' THEN SON_GIR_BR_FIAT ELSE #UnitPrice * (1- #Discount/100) END),
SON_GIR_NET_FIAT = (CASE WHEN #UnitPrice=0 OR #TransactionType != 'A' THEN SON_GIR_NET_FIAT ELSE (#UnitPrice * (1- #Discount/100)) + (#UnitPrice * #VAT/100) END)
WHERE IdItem = #IdItem AND IdStorage = #IdStorage
UPDATE Item
SET BuyingPrice = StockItem.SON_GIR_BR_FIAT where item_id = #IdItem
END
Actually Update StokItem is working it is not problem but when i want to update my Item table in here
UPDATE Item
SET BuyingPrice = StockItem.SON_GIR_BR_FIAT where item_id = #IdItem
It says Multi identifier error for StockItem.SON_GIR_BR_FIAT column.
Can you please help me! Thanks!

Answer 1

Now, it should work!
The table Inserted can contain 0, 1 or multiple rows. So, you need to use a CURSOR with the rows affected in order to UPDATE the table StockItem and Item row by row.
ALTER TRIGGER [dbo].[StockTransactionInserted]
ON [dbo].[StockTransaction]
AFTER INSERT
AS
BEGIN
SET NOCOUNT ON;
DECLARE
#IdItem int,
#IdStorage int,
#TransactionType char(1),
#Code char(1),
#Quantity decimal(18, 8),
#UnitPrice decimal(18, 8),
#Discount decimal(18, 8),
#FatAltDiscount decimal(18, 8),
#VAT decimal(18, 8)
DECLARE curStockTransaction CURSOR FOR
SELECT IdItem, IdStorage, TransactionType, Code, Quantity, UnitPrice, Discount, FatAltDiscount, VAT
FROM inserted
OPEN curStockTransaction
FETCH NEXT FROM curStockTransaction INTO #IdItem, #IdStorage, #TransactionType, #Code, #Quantity, #UnitPrice, #Discount, #FatAltDiscount, #VAT
WHILE ##FETCH_STATUS = 0
BEGIN
IF NOT EXISTS (SELECT * FROM StockItem WHERE IdItem = #IdItem AND IdStorage = #IdStorage)
BEGIN
INSERT INTO StockItem (IdItem, IdStorage, TOP_GIRIS_MIK, TOP_CIKIS_MIK)
VALUES (#IdItem, #IdStorage, 0, 0)
END
UPDATE StockItem
SET
TOP_GIRIS_MIK = TOP_GIRIS_MIK + CASE WHEN #Code = 'G' THEN #Quantity ELSE 0 END,
TOP_GIRIS_TUT = TOP_GIRIS_TUT + CASE WHEN #Code = 'G' THEN (#UnitPrice * (1- #Discount/100)) * #Quantity ELSE 0 END,
TOP_CIKIS_MIK = TOP_CIKIS_MIK + CASE WHEN #Code = 'C' THEN #Quantity ELSE 0 END,
TOP_CIKIS_TUT = TOP_CIKIS_TUT + CASE WHEN #Code = 'C' THEN (#UnitPrice * (1- #Discount/100)) * #Quantity ELSE 0 END,
ORT_BR_FIAT = CASE WHEN ((TOP_GIRIS_MIK - TOP_CIKIS_MIK) + #Quantity) = 0 THEN (ORT_BR_FIAT + (#UnitPrice * (1- #Discount/100))) / 2 ELSE ((TOP_GIRIS_MIK - TOP_CIKIS_MIK) * ORT_BR_FIAT + (#Quantity * (#UnitPrice * (1- #Discount/100)))) / ((TOP_GIRIS_MIK - TOP_CIKIS_MIK) + #Quantity) END,
SON_GIR_BR_FIAT = (CASE WHEN #UnitPrice=0 OR #TransactionType != 'A' THEN SON_GIR_BR_FIAT ELSE #UnitPrice * (1- #Discount/100) END),
SON_GIR_NET_FIAT = (CASE WHEN #UnitPrice=0 OR #TransactionType != 'A' THEN SON_GIR_NET_FIAT ELSE (#UnitPrice * (1- #Discount/100)) + (#UnitPrice * #VAT/100) END)
WHERE
IdItem = #IdItem AND IdStorage = #IdStorage
UPDATE Item
SET
BuyingPrice = StockItem.SON_GIR_BR_FIAT
FROM Item
JOIN StockItem ON (StockItem.IdItem = Item.item_id)
where
item_id = #IdItem
FETCH NEXT FROM curStockTransaction INTO #IdItem, #IdStorage, #TransactionType, #Code, #Quantity, #UnitPrice, #Discount, #FatAltDiscount, #VAT
END
CLOSE curStockTransaction
DEALLOCATE curStockTransaction
END