在MySQL数据库中使用事件保存日期

Question

I'm trying to insert dates with events in the database, first I populate table with dates and textarea, as seen in the image,. After filling the textarea, you will hit submit to save the events in the database, only the textarea with value is suppose to be stored but what is happening, all the dates is saving even without events input.

Below is the codes for saving in the database.

 if(isset($_POST['submit_calendar']))
        {
                $memo = $_POST['memo'];
                $cMonth = $_POST['cal_month'];
                $cYear = $_POST['cal_year'];

                $timestamp = mktime(0,0,0,$cMonth,1,$cYear);
                $maxday = date("t",$timestamp);
                $thismonth = getdate ($timestamp);
                $startday = $thismonth['wday'];

                for ($i=0; $i<$maxday+$startday; $i++) 
                {
                    if($i < $startday) continue;

                    if($memo == NULL)
                    {
                        $i++;
                        continue;
                    }
                    else    
                    {
                        $date = $cYear."/".$cMonth."/".($i-$startday+1);
                        $event = $memo[$i-$startday];

                        $query = "INSERT INTO calendar SET cal_date='$date', cal_event='$event'";
                        $q = mysql_query($query);
                    }
                }   
        }

Answer 1

Try

if(strlen(trim($event))>0){
  $query = "INSERT INTO calendar SET cal_date='$date', cal_event='$event'";
}