Don't ejecute a sentence if a field is empty

Hello I'm new: I need to know how can I stop a php sentence if my db is empty, for example I have writed a php sentence, if every fields from mmy db are full, there is no problem, but I delete every values from the all fields in my db when I ejecute my script mysql give me an error, Ej: $fecha = mysql_query("SELECT event_day, event_month, event_year FROM $db_table WHERE event_title = $dia_maximo"); $fecha_max = mysql_fetch_array($fecha); $fecha_maxima = $fecha_max['event_day']; $diames_maximo = $fecha_max['event_month']; wehen I ejecute the script the error message is it: Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/www/cfg/prueba/calendar_este2/index.php on line 277 sorry for my english, I'm cuban -- Este mensaje ha sido analizado por MailScanner en busca de virus y otros contenidos peligrosos, y se considera que está limpio.