Handling multiple rows in SQL Server trigger

Question

We have a database with a table called WarehouseItem where product\'s stock levels are kept. I need to know when ever this table get\'s updated, so I create

Answer 1

You could use a loop to iterate over INSERTED but it may be better to change your scalar variables into a TABLE and INSERT-SELECT from INSERTED where the IDs meet the criteria of the first two IFs

DECLARE @inserted TABLE (StockItemID INT, WarehouseID INT)

INSERT INTO @inserted (StockItemID, WarehouseID)
SELECT StockItemID, WarehouseID
FROM INSERTED i
WHERE dbo.IC_CanSyncProduct(i.StockItemID)=1
AND dbo.IC_CanSyncStock(i.WarehouseID)=1

then you can remove the if else upsert logic and use queries that further filter @inserted for the various updates and inserts that are required

;WITH ResetQueueEntry
(
    SELECT StockItemID
    FROM @inserted i
    WHERE EXISTS(SELECT 1 FROM IC_ProductCreateQueue q WHERE q.StockItemID = i.StockItemID)
    AND EXISTS(SELECT 1 FROM IC_StockUpdateQueue q WHERE q.StockItemID = i.StockItemID))
)

-- Reset [StockUpdate] Queue Entry
UPDATE IC_StockUpdateQueue 
SET Synced = 0
WHERE StockItemID IN (SELECT StockItemID FROM ResetStockUpdate);

WITH InsertQueueEntry
(
     SELECT StockItemId, 0 Synced
     FROM @inserted
     WHERE EXISTS(SELECT 1 FROM IC_ProductCreateQueue q WHERE q.StockItemID = i.StockItemID)       
     AND NOT EXISTS(SELECT 1 FROM IC_StockUpdateQueue q WHERE q.StockItemID = i.StockItemID))
)
-- Insert [StockUpdate] Queue Entry
INSERT INTO IC_StockUpdateQueue (StockItemID, Synced)
SELECT StockItemID, Synced
FROM InsertQueueEntry

WITH CreateProductEntry
(
     SELECT StockItemId, 0 Synced
     FROM @inserted
     WHERE NOT EXISTS(SELECT 1 FROM IC_ProductCreateQueue q WHERE q.StockItemID = i.StockItemID)
)
-- Insert [ProductCreate] Queue Entry
INSERT INTO IC_ProductCreateQueue (StockItemID, Synced)
SELECT StockItemId, Synced
FROM CreateProductEntry

WITH CreateStockEntry
(
     SELECT StockItemId, 0 Synced
     FROM @inserted
     WHERE NOT EXISTS(SELECT 1 FROM IC_ProductCreateQueue q WHERE q.StockItemID = i.StockItemID)
)
-- Insert [StockUpdate] Queue Entry
INSERT INTO IC_StockUpdateQueue (StockItemID, Synced)
SELECT StockItemId, Synced
FROM CreateProductEntry