Cleanup database migration script

backend/migrations/20241221174355_add-person-level.up.sql

@@ -5,23 +5,20 @@ create table if not exists people (
     created_by uuid NOT NULL,
     updated_at timestamp without time zone NOT NULL DEFAULT now(),
     updated_by uuid NOT NULL,
-    email text NOT NULL,
+    email text NOT NULL unique,
     name text NOT NULL,
     family_name text NOT NULL,
-    given_name text NOT NULL
+    given_name text NOT NULL,
+    CONSTRAINT people_pkey PRIMARY KEY (id)
 );
 
-ALTER TABLE
-    people
-ADD
-    CONSTRAINT people_pkey PRIMARY KEY (id);
-
 ALTER TABLE if exists users
-    ADD COLUMN person_id uuid REFERENCES people (id) ON DELETE SET NULL;
+    ADD COLUMN IF NOT EXISTS person_id uuid REFERENCES people (id) ON DELETE SET NULL;
 
 -- Copy accounts(users) to profiles(people)
 insert into people (created_by, updated_by, email, name, family_name, given_name) 
-select created_by, updated_by, email, name, family_name, given_name from users;
+select created_by, updated_by, email, name, family_name, given_name from users
+on conflict do nothing;
 
 -- Link accounts to profiles
 update users u set person_id = p.id from people p where p.email = u.email;