declare @portalId int

--set this value to the portalId you want to
--delete the products for
set @portalId = 0

delete {databaseOwner}[{objectQualifier}cvstore_Reviews] where productId in (select productId from {databaseOwner}[{objectQualifier}cvstore_products] where portalId=@portalId)
delete {databaseOwner}[{objectQualifier}cvstore_CategoryProduct] where productId in (select productId from {databaseOwner}[{objectQualifier}cvstore_products] where portalId=@portalId)
delete {databaseOwner}[{objectQualifier}cvstore_CartItems] where productId in (select productId from {databaseOwner}[{objectQualifier}cvstore_products] where portalId=@portalId)
delete {databaseOwner}[{objectQualifier}cvstore_products] where productId in (select productId from {databaseOwner}[{objectQualifier}cvstore_products] where portalId=@portalId)

GO