[METASVC-111] SQL: Add StoredProc to replace a collection's UUID

metasvc-server/backend-jdbi/src/main/resources/io/github/dbmdz/metadata/server/backend/impl/database/migration/R__proc_replace_collection_uuid.sql

@@ -0,0 +1,82 @@
+CREATE OR REPLACE PROCEDURE replace_collection_uuid(original uuid, new_uuid uuid)
+LANGUAGE plpgsql
+AS $$
+declare
+	urlaliases url_aliases[] := '{}';
+	urlalias url_aliases%rowtype;
+
+	ccs collection_collections[] := '{}';
+	cc collection_collections%rowtype;
+
+	cds collection_digitalobjects[] := '{}';
+	cd collection_digitalobjects%rowtype;
+begin
+	if original is null or new_uuid is null then
+		raise exception 'Both parameters (original, new_uuid) must not be null!';
+	end if;
+
+	-- store & remove url aliases
+	for urlalias in
+	  delete from url_aliases
+	  where target_uuid = original
+	  returning *
+	loop
+		-- change target uuid
+		urlalias.target_uuid := new_uuid;
+		urlaliases := urlaliases || urlalias;
+	end loop;
+
+	-- store & remove collection_collections entries
+	for cc in
+	  delete from collection_collections
+	  where child_collection_uuid = original
+	  returning *
+	loop
+		-- change child collection's uuid
+		cc.child_collection_uuid := new_uuid;
+		ccs := ccs || cc;
+	end loop;
+
+	-- store & remove collection_digitalobjects entries
+	for cd in
+	  delete from collection_digitalobjects
+	  where collection_uuid = original
+	  returning *
+	loop
+		cd.collection_uuid := new_uuid;
+		cds := cds || cd;
+	end loop;
+
+	update collections set uuid = new_uuid where uuid = original;
+	if not found then
+		raise info 'Table collections was not updated, % not found.', original;
+	end if;
+
+	-- reinsert formerly removed data sets
+	if cardinality(urlaliases) = 0 then
+		raise info 'There were no url aliases to update, target % not found.', original;
+	else
+		foreach urlalias in array urlaliases loop
+			insert into url_aliases values (urlalias.*);
+		end loop;
+	end if;
+
+	if cardinality(ccs) = 0 then
+		raise info 'Table collection_collections was not updated, child UUID % not found.', original;
+	else
+		foreach cc in array ccs loop
+			insert into collection_collections values (cc.*);
+		end loop;
+	end if;
+
+	if cardinality(cds) = 0 then
+		raise info 'Table collection_digitalobjects was not updated, collection UUID % not found.',
+		  original;
+	else
+		foreach cd in array cds loop
+			insert into collection_digitalobjects values (cd.*);
+		end loop;
+	end if;
+end;
+$$;
+