It is impossible to add a non-nullable field 'details1' to feature without specifying a default. This is because the database needs something to populate existing rows.

[Ebenezer Otchere]

Am new in django and have been getting errors in migrations, i need help

when i try to do migrations it keeps telling me this

it is impossible to add a non-nullable field 'details' to feature without specifying a default. This is because the database needs something to populate existing rows.
Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows with a null value for this column)
 2) Quit and manually define a default value in models.py.

Thank you  in advance

from django.db import models

# Create your models here.

class feature(models.Model) :

   

    name = models.CharField(max_length=100)

    extra = models.CharField(max_length=100)

    details1 = models.CharField(max_length=500)

   

class art(models.Model):

   

    name = models.CharField(max_length=100)

    details = models.CharField(max_length=500)

[Muhammed Lawal]

Enter 1 then ' ' rather. Sorry 😓

On Sat, 25 Mar 2023, 5:45 p.m. Muhammed Lawal, <lawalmuh...@gmail.com> wrote:

You are seen that error probably because you modified your models after adding some items to database already. When prompted with the error, enter 2, then ' ' an empty string. 

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[Muhammed Lawal]

You are seen that error probably because you modified your models after adding some items to database already. When prompted with the error, enter 2, then ' ' an empty string. 

On Sat, 25 Mar 2023, 1:59 p.m. Ebenezer Otchere, <swazym...@gmail.com> wrote:

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[Patricia Medina]

Thats because you have values in the database...

If you don't need the data... eliminate the 001, 002, etc files of the migration folder...(this folder is in each application folder) and applicate the migrations again.

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[Henock Lungele]

That means you have done some changes in your model python file. So you have to drop your data base, delete the migration files, recreate the database with the same name as in your configuration python file and do migrations again. This will work or you can add default parameter with a value after max_length parameter for example default="" this will work too but if you take a look to your sql codes, you have define a default behavior if the user type nothing in the input field.

I'm sorry, i speak a little bit english i'm from a french country.

Yours sincerely 

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[swazym...@gmail.com]

Thank you all, I was able to find a way around it

Is the details1 I set null = True and it worked for me

Sent from my iPhone

On 25 Mar 2023, at 7:52 PM, Henock Lungele <hlungel...@gmail.com> wrote:



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[Sandip Bhattacharya]

So what would you want for existing entries in the table which were added before you changed the model?

If you are ok with them being empty, you should use:

details = models.CharField(max_length=500, default=“”)

And run migrate again.

If you are ok instead of this column being null, then:

details = models.CharField(max_length=500, null=True, blank=True)

I don’t have a huge experience with migrations, so others can correct me if I am wrong, but intuitively I feel that defaults should be captured in code than doing one-off fixes manually while running migrations at the command line.

Thanks,

  Sandip

[Erik Manuel Herazo Jimenez]

hello, you must apply the default=None, or default="" feature, so that those fields can be filled.
ex:
details1 = models.CharField(max_length=500, default="")

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