/*
 * testlibpq.c
 *
 * Test the C version of libpq, the PostgreSQL frontend
 * library.
 */
#include <stdio.h>
#include <libpq-fe.h>
void
exit_nicely(PGconn *conn)
{
    PQfinish(conn);
    exit(1);
}
main()
{
    char       *pghost,
               *pgport,
               *pgoptions,
               *pgtty;
    char       dbName[32];
    char       password[32];
    char       conninfo[128];

    int         nFields;
    int         i,
                j;
    /* FILE *debug; */
    PGconn     *conn;
    PGresult   *res;

    printf("database name: "); 
    scanf("%s", dbName);

    printf("password: ");
    scanf("%s", password);

    sprintf(conninfo, "host = marlowe dbname = %s user = %s password = %s",
	    dbName, dbName, password);

    /* make a connection to the database */
    conn = PQconnectdb(conninfo);

    /*
     * check to see that the backend connection was successfully made
     */
    if (PQstatus(conn) == CONNECTION_BAD)
      {
        fprintf(stderr, "Connection to database '%s' failed.\n", 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 (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
      {
        fprintf(stderr, "BEGIN command failed\n");
        PQclear(res);
        exit_nicely(conn);
      }
    /*
     * should PQclear PGresult whenever it is no longer needed to avoid
     * memory leaks
     */
    PQclear(res);
    /*
     * fetch rows from the pg_database, the system catalog of
     * databases
     */
    res = PQexec(conn, "DECLARE mycursor CURSOR FOR select * from pg_tables");
    if (!res || PQresultStatus(res) != PGRES_COMMAND_OK)
      {
        fprintf(stderr, "DECLARE CURSOR command failed\n");
        PQclear(res);
        exit_nicely(conn);
      }
    PQclear(res);
    res = PQexec(conn, "FETCH ALL in mycursor");
    if (!res || PQresultStatus(res) != PGRES_TUPLES_OK)
      {
        fprintf(stderr, "FETCH ALL command didn't return tuples properly\n");
        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("\n\n");
    /* next, print out the rows */
    for (i = 0; i < PQntuples(res); i++)
      {
        for (j = 0; j < nFields; j++)
            printf("%-15s", PQgetvalue(res, i, j));
        printf("\n");
      }
    PQclear(res);
    /* close the cursor */
    res = PQexec(conn, "CLOSE mycursor");
    PQclear(res);
    /* commit the transaction */
    res = PQexec(conn, "COMMIT");
    PQclear(res);
    /* close the connection to the database and cleanup */
    PQfinish(conn);
    /* fclose(debug); */
    return 0;
}