Add primary keys to tables

food.ddl

@@ -1,6 +1,7 @@
 begin;
 
 create table weight (
+	id integer primary key,
 	date datetime default (datetime('now', '+2 hours')),
 	weight real not null
 );
@@ -53,6 +54,7 @@ group by strftime('%Y', date)
 order by date desc;
 
 create table food(
+	id integer primary key,
 	date datetime default (datetime('now', '+2 hours')),
 	food varchar not null,
 	description varchar,