Thread: Duplicate rows

so what's the problem exactly??

what's holding you from adding the primary key over fluid_id ??

in the trigger, you could use an if exists to check if the row is there before
and i guess there is no need for a loop? you can do the same per row.


On 11/12/05, Bob Pawley <rjpawley@shaw.ca> wrote:
>
> I have the following expression working in that the process.fluid_id is
> transfereed to pipe.fluid_id when the column - process.contain has a value
> of 'ip'.
> There is no transfer when the contain column holds other values. Success -
> so far.
>
> How do I keep the table pipe from being populated with duplicate rows? Among
> other reasons not to have duplicate rows,  I want to make pipe.fluid_id a
> primary key.
>
> Bob
>
> CREATE TABLE pipe (  fluid_id int4 NOT NULL);
> CREATE TABLE process( fluid_id int4 NOT NULL, process varchar, contain
> varchar) ;
>
> create or replace function base() returns trigger as $$
>  DECLARE
>  myrow RECORD;
>  BEGIN
>
>     for myrow in select * from process where contain = 'ip' loop
>          insert into pipe(fluid_id) values (myrow.fluid_id);
>          if not found then
>             do nothing ;
>
>         end if;
>     end loop;
>     return NULL;
>  END;
>  $$ language plpgsql;
>
>  create trigger trig1 after insert on process
>  for each row execute procedure base();
>
>  insert into process (fluid_id, process, contain)
>  values ('1', 'water3', 'ip');
>
>
>
>
>