If x in <listOfModels.field> syntax

问题

I have a model X with a ManyToMany field Y, my query returns a list of X's,

How do I do something like:

{% if A in X.Y %}
     Test
{% endif %}

EDIT: X is still a querySet (I'm not iterating the set).

Thanks in advance,

回答1:

You're pretty much there. You just have to return an actual queryset:

{% if A in X.Y.all %}
    Test
{% endif %}

UPDATE (based on comment)

That is not possible with template code, you need to do a filter, and the Django templating language doesn't allow passing parameters to methods. In your view, you can do:

X.objects.filter(Y=A).exists()

And pass the result into the context to be used in the template, but I'm not sure how that fits with your exact needs.

来源：https://stackoverflow.com/questions/9368386/if-x-in-listofmodels-field-syntax