NAME

       PQregisterResult - Registers sub-classes, composites and user-defined types found within a PGresult.

SYNOPSIS

       #include <libpqtypes.h>
       int PQregisterResult(PGconn *conn, int which, PGregisterType *types,
                           int count, PGresult *res);

DESCRIPTION

       The  PQregisterResult()  function  registers  the types found within a given PGresult, thus this function
       makes no calls to a PostgreSQL server since the result data is already available.

       The which argument can be PQT_COMPOSITE or PQT_USERDEFINED, but not PQT_SUBCLASS.  The only reason  being
       sub-classes don't talk to the server so they have no result set.

       The  types argument is an array containing count types to register.  This array must be identical to what
       was provided to the originating PQregisterTypes call.

       The res argument is a PGresult normally created  by  calling  PQregisterTypes  followed  by  PQgetResult.
       However,  it  is possible to create your own result via PQmakeEmptyPGresult, PQsetResultAttrs, PQsetvalue
       and call this function.  This approach is a bit risky being how the result set generated by  type  lookup
       queries are internal and subject to change.

EXAMPLES

   Using PQregisterResult
       The  example registers two composite types asynchronously.  It is worth noting that the PGresult obtained
       via PQgetResult can be cached by an application and used when creating new connections, as a way to avoid
       repeatedly performing type lookups with the server.

              PGregisterType comp_types[] = {
                   {"myschema.simple", NULL, NULL},
                   {"complex", NULL, NULL}
              };

              /* asynchronous registration */
              if (PQregisterTypes(conn, PQT_COMPOSITE, comp_types, 2, 1))
              {
                   /* example of a typical event loop */
                   for(;;)
                   {
                        int n;
                        fd_set set;
                        int fd = PQsocket(conn);
                        struct timeval tv = {0, 500000};

                        FD_ZERO(&set);
                        FD_SET(fd, &set);
                        n = select(fd + 1, &set, NULL, NULL, &tv); //or kqueue,epoll,poll,etc..

                        if (n == -1)
                        {
                             //error
                        }
                        else if (n == 0)
                        {
                             //timeout, do other work ....
                        }
                        else
                        {
                             PGresult *res;

                             PQconsumeInput(conn);
                             if(!PQisBusy(conn))
                             {
                                  /* done */
                                  if(!(res = PQgetResult(conn)))
                                       break;

                                  n = PQregisterResult(conn, PQT_COMPOSITE, comp_types, 2, res);

                                  /* This could also be cached and reused with PQregisterResult */
                                  PQclear(res);

                                  if (!n)
                                       //error, consult PQgeterror()
                             }
                        }
                   }
              }

RETURN VALUE

       On success, a non-zero value is returned.  On error, zero is returned and PQgeterror(3) will  contain  an
       error message.

EXAMPLES

       None.

AUTHOR

       A contribution of eSilo, LLC. for the PostgreSQL Database Management System.  Written by Andrew Chernow.

REPORTING BUGS

       Report bugs to <libpqtypes@esilo.com>.

COPYRIGHT

       Copyright (c) 2011 eSilo, LLC. All rights reserved.
       This  is  free  software;  see  the  source  for  copying conditions.  There is NO warranty; not even for
       MERCHANTABILITY or  FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO

       PQregisterTypes(3), pqt-handlers(3), PQputf(3), PQgetf(3)

libpqtypes                                            2011                                   PQregisterResult(3)