Once again... triggers

That who has seen all my questions about triggers, may say
"Once again this guy ??!!!". I hope you don't think so.

I've created, compiled, linked and executed my self-made triggers,
but there is still a problem.

When I try to use the trigger by launching a "delete-query", I get this
message:

------------
   PQexec() -- Request was sent to backend, but backend closed the channel
     before responding.
   This probably means the backend terminated abnormally before or while
     processing the request.

------------

I guess the "PQexec" function is called by the "SPI_exec" function.

   But where is the problem ???






_______________________________________
David Martinez Cuevas
Direccion General de Estadistica, UNAM
Tel. 622-60-80
E-mail david@estadistica.unam.mx
----------------------------------------





/*
 *  --    set of functions to define referential integrity
 *        constraints using general triggers.
 */

#include "executor/spi.h"        /* this is what you need to work with SPI */
#include "commands/trigger.h"    /* -"- and triggers */
#include <ctype.h>                /* tolower () */

int    cascada(void);


int
cascada()
{
        Trigger   *trigger;
        char       *relname;            /* referencing relation name */
        Relation        rel;                    /* triggered relation */
        HeapTuple       trigtuple = NULL;               /* tuple to being changed */
        TupleDesc       tupdesc;                /* tuple description */
        int                     ret;
    int          i;
        char                   *cad;
        char           query[256],cad2[20];

    /*
     * Some checks first...
     */

    /* Called by trigger manager ? */
    if (!CurrentTriggerData)
        elog(ERROR, "cascada: los triggers no han sido inicializados");

    /* Should be called for ROW trigger */
    if (TRIGGER_FIRED_FOR_STATEMENT(CurrentTriggerData->tg_event))
        elog(ERROR, "cascada: no se pueden procesar eventos por statement");

    /* Not should be called for INSERT */
    if (TRIGGER_FIRED_BY_INSERT(CurrentTriggerData->tg_event))

        elog(ERROR, "cascada: no se pueden procesar eventos de tipo insert");

    /* Have to check tg_trigtuple - tuple being deleted */
    trigtuple = CurrentTriggerData->tg_trigtuple;

    if (TRIGGER_FIRED_BY_UPDATE(CurrentTriggerData->tg_event))
      elog (ERROR, "cascada: no se pueden procesar eventos de tipo update");
    
    if (TRIGGER_FIRED_BEFORE(CurrentTriggerData->tg_event))
      elog (ERROR,"cascada: no se pueden procesar eventos de tipo before");

    trigger = CurrentTriggerData->tg_trigger;

    rel = CurrentTriggerData->tg_relation;
    tupdesc = rel->rd_att;
        relname = SPI_getrelname(rel);
    /*
     * Setting CurrentTriggerData to NULL prevents direct calls to trigger
     * functions in queries. Normally, trigger functions have to be called
     * by trigger manager code only.
     */
    CurrentTriggerData = NULL;

    elog (NOTICE,"Hasta aqui todo bien");
    /* Connect to SPI manager */
    if ((ret = SPI_connect()) < 0)
        elog(ERROR, "cascada: SPI_connect regres� %d", ret);
        
        
           sprintf (cad,"%s",SPI_getvalue(trigtuple,tupdesc,4));
    
    elog (NOTICE,"La tupla a borrar es del tipo: %s",cad);
    
    i = atoi(cad);    
    
    elog (NOTICE,"La tupla a borrar es del tipo: %d",i);
    
    if ( (i<0) || (i>14) || (i==6)) 
      elog (ERROR,"cascada: La tupla a borrar esta incorrecta");

    if ( i < 6  ) 
        {
           switch (i) 
               {
             case 1 : sprintf (cad2,"cuaderno");
                                break;
                 case 2 : sprintf (cad2,"software");
                      break;
                 case 3 : sprintf (cad2,"cartografico");
                      break;
                 case 4 : sprintf (cad2,"informereporte");
                      break;
                 case 5 : sprintf (cad2,"cartel");
                      break;
       
               }
        sprintf (query,"delete from %s where ProdEditorial = %s",cad2,SPI_getvalue(trigtuple,tupdesc,1));       
        }
    else 
        {   
        sprintf (query,"delete from impresion where Prodeditorial = %s",SPI_getvalue(trigtuple,tupdesc,1));
            }
    
    elog (NOTICE,"Hasta aqui todo bien con el query: \n        %s",query);         
           
        SPI_exec (query,0);                             
        SPI_finish();
        return (0);
                  
}