Query as follows:
nametable.value as product_name,
parent.type_id as parent_product_type, parent.sku as parent_sk,
child.type_id as child_product_type, child.sku child_sku
from catalog_product_entity as parent
join catalog_product_relation as link
on link.parent_id = parent.entity_id
join catalog_product_entity as child
on child.entity_id =...
removeItemByKey does not delete a product from the database. It just removes it from the product collection object.
If you want to remove products you can use