/*
 * bsp-esql.pgc
 *   Beispielprogramm DBS Vorlesung FH Niederrhein
 *   Demonstration von embedded SQL
 *   Autor: Christoph Dalitz
 *   Datum: 23.10.2002
 */

#include <stdio.h>

EXEC SQL INCLUDE sqlca;

/* für vorzeitigen Abbruch */
void exit_nicely()
{
  EXEC SQL DISCONNECT;
  exit(1);
}

/* Hauptprogramm */
int main() {
  EXEC SQL BEGIN DECLARE SECTION;
  char   name[50];
  double preis;
  char*  sqlcmd;
  char*  dbname;
  EXEC SQL END DECLARE SECTION;

  /* Connect */
  if (!(dbname = (char*)getenv("PGDATABASE"))) dbname = "template1";
  EXEC SQL CONNECT TO :dbname;
  if (sqlca.sqlcode) {
    printf("%s\n", sqlca.sqlerrm.sqlerrmc);
    return 1;
  }

  /* Abfrage mit "dynamic SQL" */
  sqlcmd = "SELECT name || ':', preis FROM produkt";
  EXEC SQL PREPARE stmt FROM :sqlcmd;
  EXEC SQL DECLARE cursor1 CURSOR FOR stmt;
  EXEC SQL OPEN cursor1;
  if (sqlca.sqlcode) {
    printf("%s\n", sqlca.sqlerrm.sqlerrmc);
    exit_nicely();
  }

  /* Loop über Ergebnisse */
  EXEC SQL WHENEVER NOT FOUND DO break;
  while (1) {
    EXEC SQL FETCH cursor1 INTO :name, :preis;
    printf("%-13s %6.2f Euro\n", name, preis);
  }

  /* Alternative: Loop mit reinen C-Mitteln */
  while (sqlca.sqlcode == 0) {
    EXEC SQL FETCH cursor1 INTO :name, :preis;
    if (sqlca.sqlcode) break;
    printf("%-13s %6.2f Euro\n", name, preis);
  }

  /* Cursor schliessen */
  EXEC SQL CLOSE cursor1;

  /* Disconnect */
  EXEC SQL DISCONNECT;

  return 0;
}