未定义标识符mysql

#include <mysql.h>
#include <iostream>

int main() {
    MYSQL *conn;
    MYSQL_RES *res;
    MYSQL_ROW row;

    const char *server = "localhost";
    const char *user = "root";
    const char *password = "your_password";
    const char *database = "your_database";

    conn = mysql_init(NULL);

    if (!mysql_real_connect(conn, server, user, password, database, 0, NULL, 0)) {
        std::cerr << "Connection error: " << mysql_error(conn) << std::endl;
        return 1;
    }

    if (mysql_query(conn, "SELECT * FROM your_table")) {
        std::cerr << "Query error: " << mysql_error(conn) << std::endl;
        return 1;
    }

    res = mysql_use_result(conn);

    while ((row = mysql_fetch_row(res)) != NULL) {
        for (int i = 0; i < mysql_num_fields(res); i++) {
            std::cout << row[i] << " ";
        }
        std::cout << std::endl;
    }

    mysql_free_result(res);
    mysql_close(conn);

    return 0;
}