CMD:players(playerid, params[])

SELECT ID FROM Accounts

new NumPlayers = mysql_num_rows();
printf("Registered players: %i", NumPlayers);

// This command "/registeredplayers" displays the amount of registered players
COMMAND:registeredplayers(playerid, params[])
{
    // Setup local variables
    new NumPlayers, Msg[128];

    // Execute the query to get all ID's from all accounts in table "Accounts"
    mysql_query("SELECT ID FROM Accounts");
    // Store the result
    mysql_store_result();
    // Count the amount of rows returned in the result
    NumPlayers = mysql_num_rows();
    // Free the result
    mysql_free_result();

    format(Msg, sizeof(Msg), "Registered players: %i", NumPlayers);
    SendClientMessage(playerid, -1, Msg);

    // Let the server know that this was a valid command
    return 1;
}

CMD:registeredplayers(playerid, params[])
{
    inline FetchResults() {
        //Result is always present
        new
            numberOfPlayers = cache_get_row_int(0, 0, dbhandle)
        ;

        //Do something with numberOfPlayers
    }

    mysql_pquery_inline(dbhandle, "SELECT COUNT(id) FROM Accounts", using inline FetchResults);
    return 1;
}