select4.c

#include <stdlib.h>
#include <stdio.h>
#include "mysql.h"

MYSQL       my_connection;
MYSQL_RES   *res_ptr;
MYSQL_ROW   sqlrow;

void display_row();
void display_header();

int main(int argc, char *argv[])
{
    int res;
    int first_row = 1;

    mysql_init(&my_connection);
    if (mysql_real_connect(&my_connection, "localhost", "root",
            "root", "test", 0, NULL, 0)) {
        printf("Connection success\n");

        res = mysql_query(&my_connection, 
            "select childno, fname, age from children where age > 5");
        if (res) {
            printf("select error: %s\n", mysql_error(&my_connection));
        } else {
            res_ptr = mysql_use_result(&my_connection);
            if (res_ptr) {
                while ((sqlrow = mysql_fetch_row(res_ptr))) {
                    if (first_row) {
                        display_header();
                        first_row = 0;
                    }
                    display_row();
                }
                if (mysql_errno(&my_connection)) {
                    printf("Retrive error: %s\n", mysql_error(&my_connection));
                }
                mysql_free_result(res_ptr);
            }
        }
        mysql_close(&my_connection);
    } else {
        fprintf(stderr, "Connection failed\n");
        if (mysql_errno(&my_connection)) {
            fprintf(stderr, "Connection error %d: %s\n", 
                    mysql_errno(&my_connection), 
                    mysql_error(&my_connection));
        }
    }
    return EXIT_SUCCESS;
}

void display_row()
{
    unsigned int field_count;
    field_count = 0;
    while (field_count < mysql_field_count(&my_connection)) {
        if (sqlrow[field_count]) {
            printf("%s ", sqlrow[field_count]);
        } else {
            printf("NULL");
        }
        field_count++;
    }
    printf("\n");
}

void display_header()
{
    MYSQL_FIELD *field_ptr;
    printf("Column details:\n");
    while ((field_ptr = mysql_fetch_field(res_ptr)) != NULL) {
        printf("\t Name: %s\n", field_ptr->name);
        printf("\t Type:");
        if (IS_NUM(field_ptr->type)) {
            printf("Numberic field\n");
        } else {
            switch (field_ptr->type) {
                case FIELD_TYPE_VAR_STRING:
                    printf("VARCHAR\n");
                    break;
                case FIELD_TYPE_LONG:
                    printf("LONG\n");
                    break;
                default:
                    printf("Type is %d, check in mysql_num.h\n", field_ptr->type);
            }
        }
        printf("\t Max width %ld\n", field_ptr->length);
        if (field_ptr->flags & AUTO_INCREMENT_FLAG) {
            printf("\t Auto increments\n");
        }
        printf("\n");
    }
}