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)