how to query a field which is a list of strings?

Using Django Using the ORM
1

Hello, everyone. I have a problem about django orm query a field which is a list of strings

For example, such a model

class Something(models):
     name = models.CharField(.....) 
     tags = models.JSONField(default=[])

The tags field records some tag information, which is a list of strings, such as ['tag1 ‘,’ tag2 ‘,’ tag3 ']

I want to know how to query the contents of tags within ‘tag1’ in this table or should i change the model design, seek help Q.Q thanks a lot!

2

The contains operator will return members of Something containing a specific tag.
e.g. To find all Something having tag2 as a member of the list tags:
somethings = Something.objects.filter(tags__contains='tag2')

Now, having said that, whether your model design should be changed depends upon your requirements for these tags.

What do these tags represent? How you plan to use them? It there a relationship between Something and SomethingElse based on those tags? Does 'tag1' in instance_1 have the same meaning as 'tag1' in instance_2? Are there other attributes associated with these tags?

These are all questions that you would need to understand the answers to in order to most properly design your models.

1 Like
3

Thank you very much. I think I should try this method. I think I misunderstood the contains method before. I thought it could only judge whether a string field contains a sub string. These labels are generally just the labels themselves, and nothing else is based on these labels. According to your suggestion, I think I should put it in this model. I’ll test the contains method and give you the results later. Thank you again for your answer.

4

This method is indeed effective, but with a little supplement, the query here is still fuzzy search. for instance.

instance_one tags is [“tag”]
instance_two tags is [ “tag1”, “tag2”]
instance_three tags is [“tag”, “tag1”, “tag2”]

filter(tags__contains=“tag”) result is all of them: instance_one, two, three…
I think containswill search whether the searched string belongs to the substring of each element in the list.
I have tried iexact. It works on the JSONField.

something = Something.objects.filter(tags__iexact="tag")  
# something is instance_one and instance_three
5

This isn’t working for me, iexact is not working for me :frowning:

6

Welcome @tasawernawaz !

If you are having an issue with which you would like assistance, please open up a new topic with the details about what you’re trying to do, how you’re trying to do it, and what’s happening as a result.