PostgreSQL's
truncate
feature is a handy way to clear out all the data from a table. If you use
truncate on a table that has a serial primary key, you may notice that
subsequent insertions keep counting up from where you left off. This is
because the sequence the table is using hasn't been restarted. Sure, you can
restart it manually or you can tell truncate to do it for you. By
appending restart identity to the end of a truncate statement, Postgres
will make sure to restart any associated sequences at 1.
truncate pokemons, trainers, pokemons_trainers restart identity;