restricting whats displayed by amount

danielhalawi

Hey,

I have a events calendar, that alows guest users to add their attendence, but what I want to do is not show the add attendee button once the amount of attendees reaches the amount of spaces on the course.

What would be the best way to do this.
The add attendee function is added to the page in an include.

Any help is much welcomed

etully

Presumably, you have some "Add Attendee" function that is generic for all calendar events. When someone clicks the button, you are probably taking some information - name, address, etc. I also presume that you have a table that keeps the event details. One of those details should be the Max number of people allowed at that event.

Method #1: If you are storing the attendee information and their event number in a table, then you can determine how many attendees are already signed up for an even like this:
As you display the calendar, count the number of people signed up for the current event like this:
select event_size from event_table where event_id=$event
select name from sign_ups where event=$event
$number = mysql_numrows($result);
If ($number < $event_size) { display "Add Attendee" button }

Method #2: This is a better method. Keep a table that stores the event number and the current number of attendees signed up for that event (call this table current_event_count or something like that). As you display the calendar, check the current signup count for that event against the Max event size for that event in the event table. If the current size is less than the Max event size then display the Add Attendee button. In this method, every time someone signs up for an event, you will need to update the count for that event in the current_event_count table.

danielhalawi

Hi,

I chose to go with the first option as this was how my tables are set up.

I created this php, from you guidance....

$event_size = mysql_query("select size from calendar_mssgs where id='$id'");
$result = mysql_query("select staffid from courses_attendance where courseid='$id'");
$number = mysql_numrows($result);
if ($number < $event_size) { echo "<img src=\"images/spaces.jpg\" alt=\"spaces\" width=\"55\" height=\"17\">"; }
else { echo "<img src=\"images/full.jpg\" alt=\"full\" width=\"55\" height=\"17\">"; }

But the if bit doesn't seem to be working, running both select's by themselves, comes out with
$event_size = 7
$results = 7 rows

so my understanding means that the else part should be showing, not the if bit, is this correct?

Any help would be grately appriciated.

etully

You're very close.

One table should list the maximum event sizes like this:

Max Event Sizes:

Event #1: 50
Event #2: 300
Event #3: 250

so if you said: select max_size from max_event_size where id=2
you would get a result of "300" meaning that there were 300 people allowed to sign up for this event

Then you have another table that lists what registrations have been recorded so far like this:

registration table:

John Smith, 1 Main Street, 555-1212, Event 7
Andy Ross, 2 Maple Street, 555-2345, Event 3
Jane Hoben, 3 Arbor Lane, 555-6666, Event 3

so if you say: select name from registrations where event=3
then you will get TWO results
so when you say: $number = mysql_numrows($result);
Then $number will be 2 (because two people have signed up for event #3 in my example)

So your if statement checks to see if $number is less than the max_event_size you got from the 1st query

if ($number < $max_event_size) { display "Add Attendee" button }

danielhalawi

Ok got it... I understand it...

But it doesn't stop showing at the max amount it waits for too many, so lets say its seven ppl max.... at seven it doesn't show the else, when you enter 8 people into the course it displays the else statement... do I need to put something extra, to say if equal or less?

etully

No. Let's say that 5 people signed up so far and the max size is 6.

Someone else comes along and views the calendar.

Your script will count the number of people who have signed up so far: The num_rows is 5. And it will do a lookup to find the max size of the event. This event has a max size of 6. So the if statement checks to see if it should show the button:

if ($number < $max_size) { display "Add Attendee" button }

So 5 IS less than six (meaning that the event isn't full yet) so it DOES display the button.

And that person signs up. So now there are 6 records in the table. So the next time the calendar is displayed, it will see a max size of 6 and 6 people already signed up.

So the if statement will check to see if 6 < 6 (and it's not) so it won't display the "Add Attendee" button which is what it's supposed to do.

You can post the relevent parts of your code if it's still not working for you and we'll take a look.