Django Migrations command workflow - django

There are three migration commands in Django:
python manage.py makemigrations
python manage.py migrate
python manage.py syncdb
In what order do these commands should be executed in terms of workflow of a basic project?
I am using Version: 1.8

syncdb is deprecated and does the same as migrate.
Whenever you make a change to your models, and when you first create them, each time you'd want to first run makemigrations to create the migration files, then migrate to apply them to your database.

Related

django runserver : relation "django_migrations" already exists

I have a django project source code, which includes several apps. The source code have been run successfully on one environment, but when transplanted to another device, with the same postgresql version(9.4.4), python version(2.7.5), and django version(1.8.5), but the runserver reports errors like this. The database has been imported in advance.
return self.cursor.execute(sql)
django.db.utils.ProgrammingError: relation "django_migrations" already exists
Try this python manage.py migrate --fake
You can read more about it in official documentation
Try troubleshooting Initial migrations using --fake-initial
python manage.py migrate --fake-initial
https://docs.djangoproject.com/en/1.8/ref/django-admin/#django-admin-option---fake-initial
If you have an empty database you can clear all your migrations and then again run migrations and migrate command.
python manage.py makemigrations
python manage.py migrate

Recreating a database for an existing django schema

I've dropped my Postgres database by accident. Then as per this solution I deleted the migration files but now can't execute the third step's command "python manage.py migrate --fake".
RuntimeError: Error creating new content types.
Please make sure contenttypes is migrated before trying to migrate apps individually.
psycopg2.ProgrammingError: relation "django_content_type" does not exist
LINE 1: ..."."app_label", "django_content_type"."model" FROM "django_co...
^
I tried running "python manage.py migrate contenttypes" and "python manage.py makemigrations contenttypes --empty" but neither work.
Using django 1.9.5
Synchronise your project first:
like this:
python manage.py syncdb
when finish you can run: python manage.py makemigrations and last python manage.py migrate

Cannot get Django 1.7 Migrations to detect proper changes to my DB.

I have a production web project running with a decent amount of data in the MySQL db. I am trying to update the database with some changes to an app called "enterlink." I've made new elements in the existing models and created new models altogether. Before this migration, I have never touched the schema of the db since originally running syncdb to create it. When I run: "python manage.py makemigrations enterlink" the below output appears(pic). My question is, why is this happening? The DB already includes all the models that it lists in the picture so why is it registering those lists of models? When I go to finish the migration by doing "python manage.py migrate" or "python manage.py migrate --fake enterlink" (pic again), I get an output shown but my database schema remains identical to the old db and any new code generates errors. Can anyone tell me what is likely the problem? I would be really appreciative of any advice. It's been very frustrating since I'm not sure what I'm missing.
What you have done is that you have ran the command python manage.py syncdb before running python manage.py makemigrations myapp and python manage.py migrate myapp. That is why syncdb created the database schema and the migration was faked because schema already exists. I will suggest to use python manage.py makemigrations myapp and python manage.py migrate myapp and not to use syncdb as its deprecated in Django 1.7.
If you change anything in your model, just run makemigrations and migrate command. Syncdb isn't necessary.
This question and relevant answers are intriguing me. Thus I want to share my experience on maintaining live database and migrations.
Tested in django1.5.5
Initializing the database:
./manage.py syncdb --noinput
./manage.py migrate
./manage.py syncdb
Now I have created the database.
Doing a migration for an app:
./manage.py schemamigration myapp --initial
./manage.py migrate myapp --fake
Now do necessary changes in your model
./manage.py schemamigration myapp --auto
./manage.py migrate myapp
Im newbie for schemamigration too, but i will explain how it works for me:
First you create app and then
./manage.py sycndb, so tables are created then you can
./manage.py makemigrations myapp --initial
so now initial migrations are created and you should apply them
./manage.py migrate myapp
now you can change your models : add,change fields, anything you want and then
./manage.py makemigrations myapp --auto
this will create migrations for changes and now you need to apply them
enter code here./manage.py migrate myapp
so this actually will create new tables in db

How to do a syncdb with django, when migrations are also involved

when I do a syncdb I get the following error everytime:
Not synced (use migrations):
- deals
- analytics
(use ./manage.py migrate to migrate these)
And when I run sudo python manage.py migrate. I get the following
Running migrations for deals:
- Nothing to migrate.
- Loading initial data for deals.
No fixtures found.
Running migrations for analytics:
- Nothing to migrate.
- Loading initial data for analytics.
No fixtures found.
I highly appreciate your help
From the output, it seems like the database is already synchronized with the migrations. There are no problematic errors. (Although you shouldn't really be root to run the migrations.)
If you're looking into creating more migrations, use the south documentation, which usually is just running the following after you modify the models:
python manage.py schemamigration --auto <APP>
And then use python manage.py migrate to apply the changes.
It looks like migrations have been already passed. Check south_migationhistory table in db.
If you want to sync new db for apps which has migrations just disable south in settings.py.
Have you ran a schemamigration initial yet?
./manage.py schemamigration deals --initial
./manage.py migrate deals
if you get the error, db already excists do this:
./manage.py schemamigration deals --initial
./manage.py migrate deals --fake

DatabaseError: no such column error

So I have a model that I wanted to add ImageField to, so I typed in
picture = models.ImageField(upload_to='media/images')
I then ran syncdb and went into the shell:
python2 manage.py syncdb
python2 manage.py shell
I then imported the model and tried
"model".objects.get(pk=1)
I get the error:
DatabaseError: no such column: people_people.picture
When I run manage.py sql for the model
"picture" varchar(100) NOT NULL
is in the database.
What solutions do you guys have? I can't delete the data in the database.
As noted in the documentation syncdb doesn't add columns to existing tables, it only creates new tables.
I suggest running
python manage.py sqlall <your_app>
Looking at the sql it outputs for the table you're changing, and then running
python manage.py dbshell
in order to manually issue an ALTER TABLE command.
In future, you might like to use a migration tool like South.
There are two possibilities that to get this error 1) You added extra field to model after doing the syncdb. 2) you added new class to model.py file in django.
Solution for this is:
First install south by using command
for windows: **easy_install south** //for that you need to go to the script folder of python folder in c drive.
for linux: **sudo easy_install south**
Then follow the steps which are included here migration tutorials
step1- python manage.py schemamigration your_app_name --initial
step-2 python manage.py migrate your_app_name
Hope this will help you.
As of 1.7 migrations within Django replaces South.
Create a new set of migration instructions by running the following command in terminal:
$ python manage.py makemigrations
Check the output in the migration folder it creates to make sure they make sense then run the following terminal command to complete the migrations:
$ python manage.py migrate
That's it.
Running migrations this way allows others to implement the same migrations instead of having to manually implement db changes on every machine using the code. On the new machine all they have to run is:
$ python manage.py migrate