notexists Join in X++

HI , Below sample used to get data from same table using 2(A,B) buffer’s.  Ex: Should get data from A which doesn’t have records in B based on catalog condition.

while select priceDiscTableSource
where priceDiscTableSource.OCSCatalogueRelation == sourceCatalog
notexists join priceDiscTableDestination
where priceDiscTableSource.ItemRelation == priceDiscTableDestination.ItemRelation
&& priceDiscTableDestination.OCSCatalogueRelation == diaCatalogDestination