feature #4: create function for constitution and title (not article in title)

resources/functions/constitution/upsert_constitution.sql

@@ -0,0 +1,32 @@
+create or replace procedure upsert_constitution(inout resource json)
+    language plpgsql as
+$$
+declare
+    titles json;
+    new_id uuid;
+begin
+    insert into constitution (version_id, created_by_id, title, annonymous)
+    select
+       version_id,
+       (resource#>>'{created_by, id}')::uuid,
+       title,
+       annonymous
+    from json_populate_record(null::constitution, resource)
+    returning id into new_id;
+
+    titles := (resource->>'titles');
+
+    insert into title (created_by_id, name, rank, constitution_id)
+    select
+        coalesce((ti#>>'{created_by, id}')::uuid, (resource#>>'{created_by, id}')::uuid),
+        ti->>'name',
+        row_number() OVER (),
+        new_id
+    from json_array_elements(titles) ti,
+    lateral json_populate_record(null::title, ti);
+
+    select find_constitution_by_id(new_id) into resource;
+end;
+$$;
+
+-- drop procedure if exists upsert_constitution(inout json);