How can I display the number of related entries? I have a template which displays a table of all the bookings on the website. The booking channel entries consist of two fields: a related user, and a related event, 1:1. There's a drop-down list of all the events at the top of the template which lists all of the events on the site. When a user clicks on an event title, the table updates to only show bookings related to that event (done by applying a class to all rows, and hiding every row which doesn't have the same class as the chosen event slug). The filter code looks like this:

&lt;form class="event-filter"&gt;
    &lt;label for="filter"&gt;Filter event: &lt;/label&gt;
    &lt;select id="filter" name="filter"&gt;
        {% for event in craft.entries.section('event') %}
        &lt;option value="i{{event.id}}"&gt;{{event.title}}&lt;/option&gt;
        {% endfor %}
    &lt;/select&gt;
&lt;/form&gt;


The bookings table displays all the events using something like this:

{% set bookings = craft.entries.section('booking').order('postDate desc') %}


Is there a way for my filter form to list my events, and display the number of bookings for each event? So it would say, for example:


First event (3 bookings)
Second event (8 bookings)


I'm sure it must be possible using relations, but I can't work out the syntax.
Try something like this:

&lt;form class="event-filter"&gt;
    &lt;label for="filter"&gt;Filter event: &lt;/label&gt;
    &lt;select id="filter" name="filter"&gt;
        {% for event in craft.entries.section('event') %}    
            {% set numEventBookings = craft.entries.section('booking').relatedTo(event).total() %}
            &lt;option value="i{{event.id}}"&gt;{{event.title}} ({{numEventBookings}} bookings)&lt;/option&gt;
        {% endfor %}
    &lt;/select&gt;
&lt;/form&gt;


But it'll generate one database query pr event, so it might be a bit inefficient, depending on your setup.