Query

I have a trigger that produces an error "returns more than one row".

My intent is to fill one table (library.specification) from another (p_id.specification). The p_id table can have multiple instances of the same fluid but I want the library table to have only one record of each fluid.

Any insight into what is happening will be appreciated.

Bob Pawley

create or replace function library_spec() returns trigger as $$
begin

Declare
fluid_type varchar ;

Begin
Select fluid into fluid_type
From p_id.specifications
Where fluid = new.fluid ;

If fluid_type <> library.specifications.fluid Then
Insert Into library.specifications (fluid) values (new.fluid_type) ;

Elseif
fluid_type = library.specifications.fluid Then
Do Nothing ;

End if ;
return null ;
end ;
end ;
$$ language plpgsql ;

create trigger libspec after insert on p_id.processes
for each row execute procedure library_spec();