delete from repetitions where habit not in (select id from habits)
delete from repetitions where timestamp is null
delete from repetitions where habit is null
delete from repetitions where rowid not in ( select min(rowid) from repetitions group by habit, timestamp )
alter table Repetitions rename to RepetitionsBak
create table Repetitions ( id integer primary key autoincrement, habit integer not null references habits(id), timestamp integer not null, value integer not null)
drop index if exists idx_repetitions_habit_timestamp
create unique index idx_repetitions_habit_timestamp on Repetitions( habit, timestamp)
insert into Repetitions select * from RepetitionsBak
drop table RepetitionsBak
pragma foreign_keys=ON