codigo da função de banco de dados

/*
    Command line to PostgreSQL database
 */
#include <stdio.h>
#include <stdlib.h>
#include "libpq-fe.h"


/* IMPORTANT change this line to setup connection */
#define DBDATA "host=localhost dbname=postgres user=postgres password=postgres";


static void
exit_nicely(PGconn *conn)
{
    PQfinish(conn);
    exit(1);
}

void print_tuplas(PGresult* res) {
    int nFields = PQnfields(res);
    int i, j;
    for (i = 0; i < nFields; i++)
        printf("%-15s", PQfname(res, i));
    printf("\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");
    }
}

int
main(int argc, char **argv)
{
    const char *conninfo;
    PGconn     *conn;
    PGresult   *res;
    int         nFields;
    int         i,
                j;

    /*
     * If the user supplies a parameter on the command line, use it as the
     * conninfo string; otherwise default to setting dbname=postgres and using
     * environment variables or defaults for all other connection parameters.
     */
    if (argc > 1)
        conninfo = argv[1];
    else
        conninfo = DBDATA;

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

    /* Check to see that the backend connection was successfully made */
    if (PQstatus(conn) != CONNECTION_OK)
    {
        fprintf(stderr, "Connection to database failed: %s",
                PQerrorMessage(conn));
        exit_nicely(conn);
    }
}