Hi All

I have three tables 

Create Table Pipe
( pipe_id serial ,
fluid_id int4 
) ;

Create Table Equipment
  (Equipment_id serial,
    fluid_id int4
) ;

Create Table Processes
   ( Fluid_id serial
    fluid varchar (15),
    ip_op_equipment varchar (5) 
    ) ;

The interface inserts the name of the fluid into column processes.fluid.

This is immediately followed by an update to column processes.ip_op_equipment 
of either "ip', 'op' or 'eq'.

Using the following trigger the fluid_id of the Process table is to be 
distributed to either the pipe or equipment under the following circumstance.

1 - If ip_op_equipment = 'ip' or 'op' insert the fluid_id into the Pipes table.
2 - If ip_op_equipment - 'eq' insert into Equipment.
-------
 Create or Replace function base() returns trigger as $$
 begin

 if new.ip_op_equipment = 'ip' or new.ip_op_equipment = 'op'
 or new.ip_op_equipment = 'oth'
 then
 insert into p_id.pipes (fluid_id) values (new.fluid_id);
 elseif
 new.ip_op_equipment = 'eq'
 then
 insert into p_id.equipment (fluid_id) values (new.fluid_id);
 end if;
 return null; 
 end;
 $$ language plpgsql ;

 Create Trigger aa1 after update on p_id.processes
 for each row execute procedure base();
-------
When I trigger 'after insert' the function doesn't work because the 
ip_op_equipment condition is an update. When I manually enter directley into 
the table this trigger works fine when both the fluid and ip_op_equipment are 
entered as one entry.

When I trigger 'after update' every row in the Processes table is inserted into 
the other tables depending on the conditionals. I end up with multiple inserts 
of the same information.

Is it possible to create a trigger that inserts only one row for each entry?

Bob Pawley

Reply via email to