Is it possible to store an array in Django model?

I was wondering if it's possible to store an array in a Django model?

I'm asking this because I need to store an array of int (e.g [1,2,3]) in a field and then be able to search a specific array and get a match with it or by it's possible combinations.

I was thinking to store that arrays as strings in CharFields and then, when I need to search something, concatenate the values(obtained by filtering other model) with '[', ']' and ',' and then use a object filter with that generated string. The problem is that I will have to generate each possible combination and then filter them one by one until I get a match, and I believe that this might be inefficient.

So, I hope you can give me other ideas that I could try.

I'm not asking for code, necessarily, any ideas on how to achieve this will be good.

Solution 1:

I'd have two advices for you:

1) Use ArrayField if you are using PostgreSQL as your database. You can read more about ArrayField here.

2) Encode your array as JSON and store it either as a plain string or using a JSONField as found here.

I'd personally prefer option number 1 since that is the cleaner and nicer way but depending on what you are actually using to store your data that might not be available to you.

Solution 2:

Yes, you can use it like this:

from django.contrib.postgres.fields import ArrayField
class Board(models.Model):
    pieces = ArrayField(ArrayField(models.IntegerField()))

However, it can only be available when using PostgreSQL for the database.

Solution 3:

If you aren't using Postgres, I recommend Django's validate_comma_separated_integer_list validator.

https://docs.djangoproject.com/en/dev/ref/validators/#django.core.validators.validate_comma_separated_integer_list

You use is as a validator on a CharField().

Solution 4:

I don't know why nobody has suggested it, but you can always pickle things and put the result into a binary field.

The advantages of this method are that it will work with just about any database, it's efficient, and it's applicable to more than just arrays. The downside is that you can't have the database run queries on the pickled data (not easily, anyway).