Filter rows if value exists in different columns

Question

We're on SQL Server 2016 and 2019

I have a data-set where I'm rolling up a parent/child relationship. I'm doing this because some of the parent rows will return a SalesValue of 0 when their children will the value we're looking for.

Here's my query:

SELECT ART.StockCode
     , BOM.Component
     , ART.QtyInvoiced
     , ART.Invoice
     , ART.SalesValue
     , ART2.SalesValue
  FROM TABLE1 ART
  JOIN TABLE2 IM
    ON IM.StockCode = ART.StockCode
  LEFT OUTER JOIN TABLE3 BOM
    ON BOM.ParentPart = ART.StockCode
   AND IM.KitType = 'K'
  LEFT OUTER JOIN TABLE4 ART2
    ON ART2.StockCode = BOM.Component
   AND ART2.Invoice = ART.Invoice

And the data it returns

StockCode   Component   QtyInvoiced    Invoice     SalesValue   SalesValue2
315128      NULL        1.000000             1         154.32          NULL
317324      NULL        1.000000             1          68.31          NULL
317350      NULL        1.000000             1         428.90          NULL
318482      NULL        1.000000             1         171.24          NULL
320058      NULL        1.000000             1          28.58          NULL
320058      NULL        1.000000             1          28.58          NULL
320058      NULL        1.000000             1          28.58          NULL
900550      NULL        1.000000             1        2396.08          NULL
900572      NULL        1.000000             1        1448.84          NULL
900581      NULL        1.000000             1        2017.96          NULL
901012      900581      1.000000             1           0.00       2017.96
901012      317350      1.000000             1           0.00        428.90
901012      317324      1.000000             1           0.00         68.31
901062      900572      1.000000             1           0.00       1448.84
901062      318482      1.000000             1           0.00        171.24

What I'm trying to do is exclude any StockCode that has a value in the Component field that has the same Invoice number

In the example above, we're looking to exclude stock codes 900581, 317350, 317324, 900572, and 318482 because they already exist in the Component field.

Here's what I'm going for:

StockCode   Component   QtyInvoiced    Invoice     SalesValue   SalesValue2
315128      NULL        1.000000             1         154.32          NULL
320058      NULL        1.000000             1          28.58          NULL
320058      NULL        1.000000             1          28.58          NULL
320058      NULL        1.000000             1          28.58          NULL
900550      NULL        1.000000             1        2396.08          NULL
901012      900581      1.000000             1           0.00       2017.96
901012      317350      1.000000             1           0.00        428.90
901012      317324      1.000000             1           0.00         68.31
901062      900572      1.000000             1           0.00       1448.84
901062      318482      1.000000             1           0.00        171.24

Answer 1

WITH cte AS (your query)
SELECT t1.*
FROM cte t1
WHERE NOT EXISTS ( SELECT NULL
                   FROM cte t2
                   WHERE t1.StockCode = t2.Component )

This works by wrapping your original query up into a CTE, then only returning rows from it if there are no other rows where the Component column is equal to the StockCode column.