The serial datatype creates a sequence in the background.  So, in your 
example, you'll have a sequence called "student_id_seq".  Your sequence was 
probably reset, dropped/created, or whatever, to cause it to feed IDs back 
that already exist in your table.

On July 2, 2004 10:22 am, [EMAIL PROTECTED] wrote:
> Hello
> i have:
> create table student(
> id                      SERIAL NOT NULL,
> name               VARCHAR(35) NOT NULL,
> primary key (id)
> );
>
> and when i try to insert like this:
> insert into student (name) values('me');
> i receive error:
> ERROR:  duplicate key violates unique constraint "student_pkey"
>
> Why ? Do i understeand correctly that SERIAL == AUTO_INCREMENT ?
> As far as i remember i used such type in the past and had no problem.
> What do i miss ?
>
> Thanx
> Michal
>
> ---------------------------(end of broadcast)---------------------------
> TIP 8: explain analyze is your friend

-- 
Michael A. Nachbaur <[EMAIL PROTECTED]>
http://nachbaur.com/pgpkey.asc

---------------------------(end of broadcast)---------------------------
TIP 9: the planner will ignore your desire to choose an index scan if your
      joining column's datatypes do not match

Reply via email to