SET search_path TO atlas, public;

-- `workspace_id` is the tenant boundary and is never nullable. PostgreSQL's
-- unqualified ON DELETE SET NULL on a composite FK clears every referencing
-- column, including workspace_id. Only the optional variant pointer may be
-- cleared when a re-collected source snapshot replaces its variants.
ALTER TABLE collection_asset_transfers
    DROP CONSTRAINT collection_asset_transfers_workspace_id_source_variant_id_fkey;

ALTER TABLE collection_asset_transfers
    ADD CONSTRAINT collection_asset_transfers_workspace_id_source_variant_id_fkey
    FOREIGN KEY (workspace_id, source_variant_id)
    REFERENCES product_variants(workspace_id, id)
    ON DELETE SET NULL (source_variant_id);