Django talk: Re: columns were not added/created to my database table (postgresql) after makemigrations/migrate

Hi Nitin,

Thank you for your comment.

I did not add any additional class in models.py.

I just added two fields under the same class, List.

class List(models.Model):

item = models.CharField(max_length=200)

completed = models.BooleanField(default=False)

created_at = models.DateTimeField('date', auto_now_add=True, null = True)

updated_at = models.DateTimeField('update', auto_now=True, null = True)

In admin.py, I did not change anything.

#this is my admin.py

from django.contrib import admin

from .models import List

# Register your models here. then go to admin page and re-load

admin.site.register(List)

Why new columns (or in other words, new fields) do not show up in my admin site? Even though I did makemigrations/migrate.

Thank you for your help!

Nori

On Tuesday, February 5, 2019 at 9:58:30 PM UTC-5, Nitin Kalmaste wrote:

You need to add python's magic method in order to return something from the models you have created. Also you have to register your models to admin.py file. You can refer Django documents for that.

On Wed, Feb 6, 2019, 8:03 AM Atsunori Kaneshige <atsu...@umich.edu wrote:
Hi, Django masters!

My app has simple models.py
just two fields like below.

#models.py
class List(models.Model):
item = models.CharField(max_length=200)
completed = models.BooleanField(default=False)

#migration 0001
class Migration(migrations.Migration):

initial = True

dependencies = [
]

operations = [
migrations.CreateModel(
name='List',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('item', models.CharField(max_length=200)),
('completed', models.BooleanField(default=False)),
],
),
]

and after makemigrations/migrate, the app was working no problem.
Then, I wanted to try adding two more fields.

#new models.py
class List(models.Model):
item = models.CharField(max_length=200)
completed = models.BooleanField(default=False)
created_at = models.DateTimeField('date', auto_now_add=True, null = True)
updated_at = models.DateTimeField('update', auto_now=True, null = True)

#migrations 0002
class Migration(migrations.Migration):

dependencies = [
('pages', '0001_initial'),
]

operations = [
migrations.AddField(
model_name='list',
name='created_at',
field=models.DateTimeField(auto_now_add=True, null=True, verbose_name='date'),
),
migrations.AddField(
model_name='list',
name='updated_at',
field=models.DateTimeField(auto_now=True, null=True, verbose_name='update'),
),
]

Django doc says that I need to add 'null = True' because I am using postgresql as my database.
Without 'null = True', the program throws an error saying that column pages_list.created_at doesn't exist etc. when I try to see the web page.
But, with 'null = True', I successfully did makemigration and migrate, then web page showed up without any problem.

But, when I go to admin, I could not find any fields that I though I created.
I also looked at the table in my postgresql, but again, there are only original columns, but not other two columns.

Do you know how to add new columns by changing models.py??
What should I take care to successfully modify models and add new columns in my database table (postgresql in my case).

I really appreciate your advice!

Looking forward to hearing from you.

Nori

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On Wed, Feb 6, 2019, 8:03 AM Atsunori Kaneshige <atsu...@umich.edu wrote:
Hi, Django masters!

My app has simple models.py
just two fields like below.

#models.py
class List(models.Model):
item = models.CharField(max_length=200)
completed = models.BooleanField(default=False)

#migration 0001
class Migration(migrations.Migration):

initial = True

dependencies = [
]

operations = [
migrations.CreateModel(
name='List',
fields=[
('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
('item', models.CharField(max_length=200)),
('completed', models.BooleanField(default=False)),
],
),
]

and after makemigrations/migrate, the app was working no problem.
Then, I wanted to try adding two more fields.

#new models.py
class List(models.Model):
item = models.CharField(max_length=200)
completed = models.BooleanField(default=False)
created_at = models.DateTimeField('date', auto_now_add=True, null = True)
updated_at = models.DateTimeField('update', auto_now=True, null = True)

#migrations 0002
class Migration(migrations.Migration):

dependencies = [
('pages', '0001_initial'),
]

operations = [
migrations.AddField(
model_name='list',
name='created_at',
field=models.DateTimeField(auto_now_add=True, null=True, verbose_name='date'),
),
migrations.AddField(
model_name='list',
name='updated_at',
field=models.DateTimeField(auto_now=True, null=True, verbose_name='update'),
),
]

Django doc says that I need to add 'null = True' because I am using postgresql as my database.
Without 'null = True', the program throws an error saying that column pages_list.created_at doesn't exist etc. when I try to see the web page.
But, with 'null = True', I successfully did makemigration and migrate, then web page showed up without any problem.

But, when I go to admin, I could not find any fields that I though I created.
I also looked at the table in my postgresql, but again, there are only original columns, but not other two columns.

Do you know how to add new columns by changing models.py??
What should I take care to successfully modify models and add new columns in my database table (postgresql in my case).

I really appreciate your advice!

Looking forward to hearing from you.

Nori

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To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/a1d71d4c-1500-4972-af57-dc23f5d1ff20%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

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Django talk

Tuesday, February 5, 2019

Re: columns were not added/created to my database table (postgresql) after makemigrations/migrate

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