How can I update a table using the following CROSS APPLY? - tsql

Question

UPDATE ItemDim_DEV
set ActiveFlag = 0,
EndUTCDate = GETUTCDATE()
from (select i.SKU, i.itemname, i.category, i.CategoryInternalId, i.itemtype, i.IsActive, i.assetaccount, i.InternalId,
ni.sku,
ni.itemname,
ni.class_name,
ni.productclass,
ni.ItemType,
ni.isactive,
ni.assetaccount,
i.CalculatedHash, ni.hashid
from (
SELECT i.*
FROM itemDim_Dev i
WHERE i.SourceSystem = 'NetSuite'
--and InternalId = '1692'
) i
CROSS APPLY (
SELECT (CONVERT([binary](64),hashbytes('SHA2_512',
concat (ISNULL(im.TargetSKU, ni.sku), ni.itemname, pc.class_name, ni.productclass, ni.ItemType,
CAST(CASE WHEN ni.IsInactive = 'T' THEN 0 ELSE 1 END AS BIT ), ni.assetaccount)))) hashid,
ISNULL(im.TargetSKU, ni.sku) sku,
ni.itemname,
pc.class_name,
ni.productclass,
ni.ItemType,
CAST(CASE WHEN ni.IsInactive = 'T' THEN 0 ELSE 1 END AS BIT ) isactive, ni.assetaccount
FROM NetSuiteInventory ni
INNER JOIN Product_Class pc ON ni.productclass = pc.class_id
LEFT JOIN ItemMapping im ON ni.sku = im.SourceSKU
WHERE ni.ItemInternalId = CAST(i.InternalId as bigint)
and
(CONVERT([binary](64),hashbytes('SHA2_512',
concat (ISNULL(im.TargetSKU, ni.sku), ni.itemname, pc.class_name, ni.productclass, ni.ItemType,
CAST(CASE WHEN ni.IsInactive = 'T' THEN 0 ELSE 1 END AS BIT ), ni.assetaccount)))) = i.CalculatedHash
) ni
I understand that I can put a select after the from of the update but in the CROSS APPLY that is in the query starts with a select as in the second one, can you help me please.

Answer 1

Make a join to the target table
UPDATE A
SET XXX = YYY
FROM ItemDim_DEV A
JOIN (
--huge SELECT that I recommend you try to shorten in the next questions
CROSS APPLY (any secrets...)
) B ON A.PK = B.PK