Sequence does not reset after truncating the table

Question

I use SELECT lastval() to get wrong serial id after truncated the table.

when I truncate the table, I use SELECT lastval(), I got the wrong ID/

Answer 1

The best way to reset a sequence to start back with number 1 is to execute the following after you have successfully truncate it:

ALTER SEQUENCE __seq RESTART WITH 1

So, for example for the users table it would be:

ALTER SEQUENCE users_id_seq RESTART WITH 1