ManyRelatedManager object is not iterable

Question

Trying to do this:

wishList = WishList.objects.get(pk=20)
matches = [val for val in Store.attribute_answers.all() if val in wishList.attribute_answers]

And get this...

'ManyRelatedManager' object is not iterable

Both fields are many-to-many so how can this be done?

https://stackoverflow.com/questions/6704749/relatedmanager-object-is-not-iterable-django — AnonymousUser, Aug 12 '22 at 06:02

Aidan Ewen · Accepted Answer · 2020-03-03T11:45:43.793

Try

matches = [val for val in Store.attribute_answers.all() if val in WishList.attribute_answers.all()]

Notice the parenthesis at the end of WishList.attribute_answers.all(). Adding the parenthesis invokes the all function to return an iterable.

If you include the parenthesis you're saying "give me all the values in the stores answers so long as that value is also in the wish lists answers". Without the parenthesis you're asking for all the values from the store's answers that are also in the all function, which is meaningless. The all function is not an iterable (it's a function that returns an iterable)

score 74 · Answer 2 · edited Sep 08 '21 at 05:19

74

Sounds like you are looking for something like

Store.attribute_answers.all()

edited Sep 08 '21 at 05:19

Sabito stands with Ukraine

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answered Feb 17 '13 at 12:16

second

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andyw · Answer 3 · 2020-05-31T14:53:28.903

If you are doing this in a template:

{% for room in study.room_choice.all %}
  {{ room }}
  {% empty %}
  empty list!
{% endfor %}

UPDATE

If you have a through table, you can access the elements in that table (as detailed here) like so (note, you use the through table name, in lowercase, suffixing _set):

{% for roominfo in participant.roomchoicethru_set.all %}
  {{ roominfo.room}} {{ roominfo.telnumber}}
{% endfor %}

score 48 · Answer 4 · edited Dec 11 '21 at 20:34

48

all()

For everyone who finds reading code in questions as TL;DR

Instead of query_set.many_to_many

you should use query_set.many_to_many.all()

edited Dec 11 '21 at 20:34

Maifee Ul Asad

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answered Jul 24 '18 at 14:55

Qback

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This should have been the accepted answer, can't get any simpler – Malik Bagwala Jul 09 '20 at 08:02
And in a template it is `whatevertheobject.themanytomanyfield.all` without parenthesis. – kontur Nov 06 '22 at 16:31

score 0 · Answer 5 · answered Aug 01 '22 at 22:38

Answers are good and I just needed to add a point for easier understanding.You couldn't query the field where many to many is set because it returns and objects not a list of options.It is better to get the data from the field in your views then pass it to the templates.For example if you have posts model where each post has many to many relations with Tags model.

class Tag(models.Model):
      ""
class Post(models.Model):
      tags = models.ManyToManyField(Tag)

If you tried post.tag.caption it will return this error.You should pass tags as a seperate idintifier in your views.

"post": identified_post,
"post_tags":identified_post.tags.all()

instead of passing only

"post": identified_post

score -1 · Answer 6 · answered Jan 10 '20 at 13:55

-1

I keep hitting this question whenever this problem comes up. Particularly when trying to actually iterate over a manytomany in a function.

As a template you can do:

array = many_to_many.all()
for x in many_to_many:
  function here

answered Jan 10 '20 at 13:55

Alex Tomlinson

9

score -2 · Answer 7 · answered Mar 14 '19 at 10:10

Here busines_type is foreign_key in profile model

pro = Profile.object.filter(user=myuser).first()
business_type = pro.business_type.all()
if business_type:
    b_type = ''
    for b in business_type:
        b_type += str(b.type)+' '
        a = b_type

ManyRelatedManager object is not iterable

7 Answers7

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