Rails seed: How to truncate DB table?

Before seeding test data into DB table I need to truncate the table (I need to reset primary key), I am trying to do that this way:

ActiveRecord::Base.connection.execute("TRUNCATE users")

but when I print out data from DB, I still don't see counting primary key from 1.

What am I doing wrong?

EDIT:

Also, I've tried manually run in terminal to PostgreSQL database

truncate users

But the primary count still doesn't start from 1.

SOLUTION:

In Postgres, run:

ALTER SEQUENCE users_id_seq RESTART WITH 1;