Create find_follow.sql

src/main/resources/sql/functions/follow/find_follow.sql

@@ -0,0 +1,25 @@
+create or replace function find_follow(
+    _target_id uuid,
+    _citizen_id uuid,
+    out resource json,
+    out following boolean
+) language plpgsql as
+$$
+begin
+    select to_json(t)
+    into resource
+    from (
+        select
+            f.*,
+            json_build_object('id', f.target_id, 'reference', f.target_reference) as target,
+            find_citizen_by_id(f.created_by_id) as created_by
+        from follow as f
+        where f.created_by_id = _citizen_id
+          and f.target_id = _target_id
+    ) as t;
+
+    select resource is not null into following;
+end;
+$$;
+
+-- drop function if exists find_follow(uuid, uuid);