How to store a dictionary in a Django database model's field?

Question

I want to store this list of dictionarys in a Django database:

h =  [

{'sale_id': 14,
  'name': 'Macarena',
  'fecha': datetime.date(2021, 3, 11),
  'debe': 500.0},
 {'sale_id': 14,
  'name': 'Macarena',
  'fecha': datetime.date(2021, 4, 11),
  'debe': 500.0},
 {'sale_id': 15,
  'name': 'Yamila',
  'fecha': datetime.date(2021, 4, 14),
  'debe': 2000.0}

]

I've tried this:

h = tabla_creditos()

class Creditos1(models.Model):

    sale_id = models.IntegerField(default=0)
    name = models.CharField(max_length=150)
    fecha = models.DateTimeField(default=datetime.now)
    debe = models.IntegerField(default=0)

for i in range(0,len(h)):
    Creditos1.objects.create(name=h[i]['name'], sale_id=h[i]['sale_id'], fecha=h[i]['fecha'], debe=h[i]['debe'])

where "h" is that dictionary, which results from "tabla_creditos()" function. And then, I tried to create the values for the DB with "objects.create" but I got duplicated values stored in DB:

So, how can I store that dict in the DB?

I found this solution: How to store a dictionary in a Django database model's field but none of the answers helped me.

Thanks!

EDIT With the Rohith answer, I got this:

But I would like something like this, transform every key of the dict in a DB column:

Try using Django JSON field https://docs.djangoproject.com/en/3.2/ref/models/fields/#jsonfield — Nikita Tonkoskur, Jul 04 '21 at 20:51
Does this answer your question? [How to store a dictionary on a Django Model?](https://stackoverflow.com/questions/402217/how-to-store-a-dictionary-on-a-django-model) — Brian Destura, Jul 05 '21 at 04:59
If you use a JSON or String Field to store the dictionary, than everything is stored in one Field (1 column). You cannot do DB stuff like filter by sale_id anymore. Thats probably not what you want? If I'm guessing right, than you are going to store the Data of a dict into a DB not the dict itself. — Lukr, Jul 06 '21 at 16:09

Rohith Samuel · Accepted Answer · 2021-07-08T15:16:46.577

There are a few ways to save a Dictionary in Models. I am mentioning the use of the JSON Field.

If you are using PostgreSql as your database then you have access to JSON Field. you can read about it in the documentation. This will let you save the dictionary as a JSON File which Django supports

Eg:

from django.contrib.postgres.fields import JSONField

class Creditos1(models.Model):
    dict_info = JSONField(default=dict)

In your Code

sample_dict =  [

{'sale_id': 14,
  'name': 'Macarena',
  'fecha': datetime.date(2021, 3, 11),
  'debe': 500.0},
 {'sale_id': 14,
  'name': 'Macarena',
  'fecha': datetime.date(2021, 4, 11),
  'debe': 500.0},
 {'sale_id': 15,
  'name': 'Yamila',
  'fecha': datetime.date(2021, 4, 14),
  'debe': 2000.0}

]

credit = Creditos1.objects.create(dict_info=sample_dict)

If you are using any other databases, I would recommend creating the field as CharField(). Then encode the dict as a JSON string and save that string into Credit. Then you can decode the JSON string back.

Eg:

class Creditos1(models.Model):
    dict_info = CharField(blank=True, null=True)

In your Code:

import json
sample_dict =  [
    
    {'sale_id': 14,
      'name': 'Macarena',
      'fecha': datetime.date(2021, 3, 11),
      'debe': 500.0},
     {'sale_id': 14,
      'name': 'Macarena',
      'fecha': datetime.date(2021, 4, 11),
      'debe': 500.0},
     {'sale_id': 15,
      'name': 'Yamila',
      'fecha': datetime.date(2021, 4, 14),
      'debe': 2000.0}
    
    ]
    encoded_json = json.dumps(sample_dict)
    credit = Creditos1.objects.create(dict_info=encoded_json)

In order to get the values of the the dict, you can use json.loads()

decoded_data = json.loads(credit.dict_info)
print(decoded_data[0]["name"])

UPDATE

From my understanding, The function tabla_creditos() is still unclear and that might be the reason for the multiple objects being created or it can even be that you might not have cleared the Database (Use the code to delete all records Creditos1.objects.all().delete() ).

If you want to Save the list of dictionaries as each object, (Assuming you have a clean DB) Your Code:

h = some_func()
uniquefied_list = list({v['sale_id']:v for v in h}.values())
for x in range(0, len(uniquefied_list)):
    Creditos1.objects.get_or_create(name=h[x]["name"], debe=h[x]["debe"]....)

Here, get_or_create would be a better way to handle this Here is the documetation

Hope this resolves your issue.

Thanks! But I'm using SQLite and I got this error: "sqlite3.InterfaceError: Error binding parameter 0 - probably unsupported type." — Silvio Aranda, Jul 04 '21 at 21:21
@SilvioAranda: As I mentioned, This works for PostgreSQL. If you are using SQLite We might have to look at other options, I will update the answer when I can :) — Rohith Samuel, Jul 05 '21 at 04:14
Thanks Rohith, it works but I got another problem, I will update my question. I hope you can help me :) Thanks again! — Silvio Aranda, Jul 05 '21 at 14:04
@SilvioAranda I have updated the Answer, if you have other quires please create another thread and I can have a go at that (You can add it as a comment here). — Rohith Samuel, Jul 06 '21 at 04:07
Thanks Rohith, the "uniquefied_list" returns unique "sale_id" but I got 2 "sale_id" with different dates ("fecha") and I would like to keep both because are two different sales. I created another thread: https://stackoverflow.com/questions/68273452/how-to-save-a-list-of-dictionaries-as-each-object-in-a-django-database-models-f. Thanks! — Silvio Aranda, Jul 06 '21 at 15:36
@SilvioAranda Then you need not use the uniquefied_list, as long as you make sure the uniqueness in your function, That's the reason I suggested the get_or create attr. Please accept the answer if you think it was correct. — Rohith Samuel, Jul 08 '21 at 15:18

score 0 · Answer 2 · answered Jul 04 '21 at 22:19

0

Use JSON Field. note that its not supported in SQLite

answered Jul 04 '21 at 22:19

dchoruzy

249
2
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How to store a dictionary in a Django database model's field?

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