/*
          * testlibpq.c
          *   Test the C version of LIBPQ, the POSTGRES frontend library.
          *
          *
          */
         #include </usr/include/stdio.h>
         #include </usr/include/pgsql/libpq-fe.h>
         void
         exit_nicely(PGconn* conn)
         {
          void PQfinish(PGconn *conn);
           exit(1);
         }

         main()
         {
           char *pghost, *pgport, *pgoptions, *pgtty;
           char* dbName;
           int nFields;
           int i,j;

         /*  FILE *debug; */

           PGconn* conn;
           PGresult* res;

           /* begin, by setting the parameters for a backend connection
              if the parameters are null, then the system will try to use
              reasonable defaults by looking up environment variables
              or, failing that, using hardwired constants */
           pghost = NULL;  /* host name of the backend server */
           pgport = NULL;  /* port of the backend server */
           pgoptions = NULL; /* special options to start up the backend server */
           pgtty = NULL;     /* debugging tty for the backend server */
           dbName = "bhavna";

           /* make a connection to the database */
           conn = PQsetdb(pghost, pgport, pgoptions, pgtty, dbName);

           /* check to see that the backend connection was successfully made */
           if (PQstatus(conn) == CONNECTION_BAD) {
             fprintf(stderr,"Connection to database %s failed.0",
dbName);
             fprintf(stderr,"%s",PQerrorMessage(conn));
             exit_nicely(conn);
           }

         /*  debug = fopen("/tmp/trace.out","w");  */
         /*   PQtrace(conn, debug);  */

           /* start a transaction block */

           res = PQexec(conn,"BEGIN");
           if (PQresultStatus(res) != PGRES_COMMAND_OK) {
             fprintf(stderr,"BEGIN command failed0");
             PQclear(res);
             exit_nicely(conn);
           }
           /* should PQclear PGresult whenever it is no longer needed to avoid
              memory leaks */
           PQclear(res);

           /* fetch instances from the pg_database, the system catalog of databases*/
           res = PQexec(conn,"DECLARE myportal CURSOR FOR select * from pg_database");
           if (PQresultStatus(res) != PGRES_COMMAND_OK) {
             fprintf(stderr,"DECLARE CURSOR command failed0");
             PQclear(res);
             exit_nicely(conn);
           }
           PQclear(res);

           res = PQexec(conn,"FETCH ALL in myportal");
           if (PQresultStatus(res) != PGRES_TUPLES_OK) {
             fprintf(stderr,"FETCH ALL command didn't return tuples properly0");
             PQclear(res);
             exit_nicely(conn);
           }

           /* first, print out the attribute names */
           nFields = PQnfields(res);
           for (i=0; i < nFields; i++) {
             printf("%-15s",PQfname(res,i));
           }
           printf("0");

           /* next, print out the instances */
           for (i=0; i < PQntuples(res); i++) {
             for (j=0  ; j < nFields; j++) {
               printf("%-15s", PQgetvalue(res,i,j));
             }
             printf("0");
           }

           PQclear(res);

           /* close the portal */
           res = PQexec(conn, "CLOSE myportal");
           PQclear(res);

           /* end the transaction */
           res = PQexec(conn, "END");
           PQclear(res);

           /* close the connection to the database and cleanup */
                         exit_nicely(conn);

         /*   fclose(debug); */
         }