I've just created a new model in project/posts/models.py but manage.py migrate completes without creating the new model. Similarly manage.py makemigrations detects no changes either and returns No changes detected. Does anyone know why the new model is not detected?
Is your app posts listed in INSTALLED_APPSin your settings.py file? That might be the issue.
Also you can try with:
manage.py makemigrations posts
Related
We are fairly new to Django. We we have an app and a model. We'd like to add an 'Category' object to our model. We did that, and then ran 'python manage.py makemigrations'.
We then deploy our code to a server running the older code, and run 'python manage.py migrate'. This throws 2 pages of exceptions, finishing with 'django.db.utils.ProgrammingError: (1146, "Table 'reporting.contact_category' doesn't exist")'
This seems to be looking at our models.py. If we comment out Category from our model, and all references to it, the migration succeeds.
I thought that the point of migrations is to make the database match what the model expects, but this seems to require that the model match the database before the migration.
We clearly are doing something wrong, but what?
I believe you skipped some migration in the server, so now you are missing some tables (I have been in that situation. Ensure migrations directories are on your .gitignore. You CAN NOT check in migrations files, you have to run makemigrations on the server). This can be solved by tracing back up to the point the database and models files match, but it is a risky process if it is your production database, so you should make a full backup before proceeding, and try the process on a different computer before.
This would be my advice:
Delete migration files from the server.
Comment the models that rise the error.
Set the server's migration history to the point the
database is, using python manage.py makemigrations and python manage.py migrate --fake-initial (this will update the migration files without actually attempting to modify the database).
Uncomment the models that raise the error.
Run python manage.py makemigrations and python manage.py migrate.
If, after you comment the models that raise the exception, you get a different exception, you have to keep on commenting and attempting again. Once a migrations succeeds, you can uncomment all commented models and make an actual migration.
Remember to run python manage.py makemigrations if you made changes to the models.py then run python manage.py makemigrations
Both commands must be run on the same server with the same database
I deployed a website on python anywhere. Then I planed on adding an extra model for more functionality. I added that model offline and it works fine but when I made changes to the deployed website the bash console didn't detect any migrations. I thought there was something wrong with the model so I added some sample models to check but even those weren't getting detected when I used
python manage.py makemigrations
the same happened when I used
python manage.py migrate I read up the docs but there isn't a problem with the code
I have trouble with django model migrations.
I have some models in my app, and I already have some data inside.
When I added some models in my application, and I run makemigrations, the app report that there is no change.
I know that sometimes some errors came when migrate, so I delete django_migrations table in my database and run makemigrations again, and now program found my new fields.
The problem now is that if I run migrate system tell me that some tables already exist. (Which is ok and correct, because they do). I don't want to delete those tables, because I have data already inside.
I can't run migrate --fake, because program will think that I already have all the tables, which is not true.
So, I am looking for a way to tell the program : run migration, if table exist skip it. (--fake it)
Another question is why is this happening to me, that makemigrations don't recognise my changes (some cache problems,...)?
How about doing this way ?
python manage.py makemigrations
(Skip this step if you have already have migration file ready)
It will create migrations for that package lets say with a name like 0001_initial.py
Edit the file manually so that you delete all models there except that was already created in database.
Now you do a fake migration. This will sync your database with models.
python manage.py migrate --fake
Then run makemigrations again to have rest of the tables created along with a new migration file.
python manage.py makemigrations
Regarding your other question, Why makemigrations didn't recogonize your models can be because of reasons like:
Migrations for those changes are already there in some migration file.
You missed it to mention package_name in INSTALLED_APPS but i believe you did it here.
every time you make changes to your models, try these steps :
python manage.py makemigrations [your app name]
then:
python manage.py migrate
it should work fine. but remember if you have already data(rows) in your tables you should specify the default value for each one the queries.
if not, Django prompt you to specify the default value for them
or you can just try to use blank=True or null=True in your fields like below :
website = models.URLField(blank=True)
the possible cause or this is that you have another migration in the same folder starts with the same prefix... maybe you make another migration on the same table on another branch or commit so it's saved to the db with the same prefix ie: 00010_migration_from_commit_#10, 00010_migration_from_commit_#11
the solution for this is to rename the migration file like this 00011_migration_from_commit_#11
I tried to edit the related migration file and commented the part where it creates that specific column, then ran python manage.py migrate
The main problem is the existing tables that are disabling the migration of the new tables, so the solution is straight-forward:
** Try to add managed = False to the existing dB so it won't be detected by migrate
** Redo it for all existing old tables :
class Meta:
managed=False
It sometimes gets boring when we have a lot of tables in the same application but it works perfectly!
I'm using django 1.9.6. I recently deleted my migrations and ran migrate --run-syncdb and makemigrations my_app. Today I added a new field to one of my models:
models.py:
value = models.PositiveSmallIntegerField(null=True)
I tried to migrate the changes, but makemigrations doesn't detect the change. It's just the development version, so I can resync (I don't have to preserve the data), but running --run-syncdb again doesn't detect it either.
Why isn't this migrating?
Delete every past migration files and __pycache__ files except __init__
then:
python manage.py makemigrations yourApp
After that make sure that the db is the same as the code in model.py (remove new changes) and run next line:
python manage.py migrate --fake-initial
Now add all your changes in the model.py and run next lines:
python manage.py makemigrations
python manage.py migrate
Best Regards,
Kristian
I had the same issue. I realised I had a property defined on the model with the same name as a field I was trying to add on the model. Ensure the model doesn't have a model property/method with the same name as the field you are trying to add.
You should not delete migrations, you should squash them. If you simply deleted the files you likely messed things up, the easiest way to recover is re-sync your code to get the files back. A more complex route is to delete all the records from the django_migrations table and re-init the migrations from scratch but there is more steps/issues than I can really get into and I don't recommend it.
The reason makemigrations is not detecting the change is likely because there is no migrations folder in that app. If you run python manage.py makemigrations your_app --initial it might detect and generate the migrations or it might freak out because of the difference in your files and the django_migrations table.
The --run-syncdb command is great when you don't care about the data, usually before you actually deploy but once you start using migrations you should not use the --run-syncdb command anymore. For instance, during initial development here is the code I run every model change instead of dealing with migrations:
dropdb mydb && createdb mydb && python manage.py migrate --run-syncdb && python manage.py loaddata initial
I store all the initial data in a fixtures file and the command wipes out the entire database, the --run-syncdb rebuilds the schema, and the initial data is loaded while skipping actual migration files.
So, if you don't care about any of your data or can easily move it to a fixture than you can drop and re-create the DB. You are then free to delete all migration folders and you can use the command above until you go live and need to move to using migrations.
*** UPDATE FOR DJANGO 1.11 *** STILL USING ON 3.2.5 ***
I started using Django 1.11 and noticed the test framework can fail if you have dependencies on framework models and don't actually have migrations. This is the new command i'm using to wipe everything out and start over while still developing.
set -e
dropdb yourdb
createdb yourdb
find . -name "migrations" -type d -prune -exec rm -rf {} \;
python manage.py makemigrations name every app you use seperated by space
python manage.py migrate
python manage.py loaddata initial
I put this in a builddb.sh at the root of my project (next to manage.py) so I can just run ./builddb.sh. Be sure to delete it on deploy so there is no accidents!
Try creating a migrations folder that contains an empty __init__.py file inside your app folder if there is no migrations folder already. And make migrations.
In my case, I created a new project and created an app. The python manage.py makemigrations returned no change detected although I had added a handful of models.
Found out that you need to manually add the name of your app in the INSTALLED_APPS list inside your settings.py file. Unless you do that, no change in the migration of that app can be detected.
If you're deleting a model, and expecting the changes to be picked up in migrations, ensure that the model doesn't have a *.pyc still lying around.
Another case is abstract classes. Make sure that your model’s metaclass does not have the abstract = True property.
I have a django 1.8 app working with a db.
I'm trying to change the schema of a table using the built-in migration.
Here are the steps I did:
In my dev invironment, I grabbed the app source and ran
python manage.py sycdb
then I ran
python manage.py loaddata ~/my_data.json
then I modified modes.py. Added a field and renamed a field...all from the same table 'TABLE1' which had no data.
then
python manage.py makemigrations myapp
python manage.py migrate
Error: django.db.utils.OperationalError: table "myapp_someother_table" already exists
then ran
python manage.py migrate --fake-initial
worked!
but when I browsed to the admin page for TABLE1, I get this error:
OperationalError: no such column: myapp_table1.my_new_field_id
I checked the db and yes, there is no such column.
How can I procceed from here? I prefer to fix this via django.
If I fix it straight in the db, then the migration goes out of sync.
Migrations do not automagically see that you have made changes. Migrations detect changes by comparing the current model with the historical model saved in the migration files.
In this case, you didn't have any historical models, since you didn't have any migrations. Django was not able to detect any changes in your models, even though they were different from your database.
The correct way to make changes to your model is to first run manage.py makemigration <my_app>, and then make the changes to your model, followed by another manage.py makemigrations.
You might not be able to do it via pure django and keep your data. I don't have personal experience with south but there are a lot of mentions if this tool. Just in case if nothing else works for you...
Here is what I did to make things work, but there must be a better way so please add more answers/comments...
I deleted the sqlite db and the migration folder
I made the desired changes to model.py
ran syncdb
ran loaddata to load the json data dump that I had saved previously.
just started the dev server