django migrations does not update database - django

I have django app already online and running. I created new model and if I do the makemigrations, it is working fine, but if I want to migrate it, then I receive Running migrations:No migrations to apply. Even though that I made a change. The change is also in the migration file. I am using postgresql with it. I tried to delete the migration file and create it once more, but it did not help. Any idea what might be wrong?

Looks like some migrations are marked as applied incorrectly in the database. This can be solved by using the --fake flag [Django docs] to mark an appropriate migration as applied / some migrations as unapplied.
Suppose that your app is named myapp and the migration 0004 is applied properly to the database (you are trying to apply 0005 or further which doesn't work) then you will run the following command:
python manage.py migrate myapp 0004 --fake
Note: myapp and 0004 is an example, do this according to your apps name and which migrations are applied.
Edit: It appears that you have deleted the migrations. But thankfully have some version control in place. Best would be to get the migration files back from the version control. If for some reason you are unable to do that, revert the models to how they were before their changes and make sure no migration files exist for now. Next generate the migration files by running makemigrations (check that they are as expected and your database state corresponds to these generated files). Next run the following two commands:
python manage.py migrate <appname> zero --fake
python manage.py migrate <appname> --fake
The first one will mark all migrations as unapplied for the app. The second one will mark all the migrations as applied. Next you will add the changes you wanted to make back to the models and migrate again.

Related

How can I update sqlite database in django without original migration files and preserve the data in db.sqlite3 at the same time?

I am a beginner in django. I accidentally deleted the original migration files and the only remaining related file is db.sqlite3. Now I made some changes to models.py and want to update my database while preserving the previous data in db.sqlite3. How can I do this? Will python manage.py makemigrations work?
Nop.
What you can do is run make migrations before your changes.
Run
Python manage.py migrate --fake
This will make a migration for your table as it is and then mark it as applied. Now you can make your changes and run make migration... Migrate

relation "django_admin_log" already exists

when i try to run python manage.py migrate i run into following error
Upon running python manage.py run migrations it says no changes detected. and when i runserver it gives me warning that i have unapplied migrations as well.i have been searching internet for two hours but got not solution. Someone knowing the solution please share :)
The table in your database that stores migration data to keep track of what has been applied is out of date. Try running python manage.py migrate --fake
Try python manage.py makemigrations [app name] and if still, this does detect changes then delete the folder named migrations which is inside your application folder and then use this python manage.py makemigrations [app name]. Once migration happens successfully do the python manage.py migrate.
Don't Try This at Home
I faced this issue, i make two changes,
change AUTH_USER_MODEL, so i have one migraiton about it
second one add new field for my folder_model(migration name: folder_model 0021)
When my first migrate attempt(I already run makemigrations commands on local so i have migration files), it says;
django.db.migrations.exceptions.InconsistentMigrationHistory: Migration admin.0001_initial is applied before its dependency account.0001_initial on database 'default'
This error reiases because i change the AUTH_USER_MODEL in the middle of the project, normally you have to remove your database and fresh start from the beginnig(also truncate migrations etc.), according to Django doc -> https://code.djangoproject.com/ticket/25313
To fix this issue, you don't have to delete all migrations on db, just delete the migrations about admin(not from project just database)
After that just run
python manage.py migrate
It throws relation "django_admin_log" already exists. For this issue, run:
python manage.py migrate --fake
That's it, but not completely. Make fake migration act like you already make your all migrations successfully and save these on db. The issue came here that i have another migration about folder_model 0021 and with fake migration it doesn't applied to my database table but saved to db_migrations table.
So fix this issue, delete the folder_model 0021to database migration table (just 0021 not all folder_model migrations).
After delete just run python manage.py migrate
Everything is fine!

Django manage.py: Migration applied before its dependency

When running python manage.py migrate I encounter this error:
django.db.migrations.exceptions.InconsistentMigrationHistory: Migration
<appname>.0016_auto_<date2>_<time2> is applied before its dependency
<appname>.0001_squashed_0015_auto_<date1>_<time1>
running showmigrations returns:
<appname>
[X] 0001_squashed_0015_auto_<date1>_<time1> (15 squashed migrations)
[X] 0016_auto_<date2>_<time2>
[ ] 0017_<modelname>_squashed_0019_auto_<date3>_<time3> (3 squashed migrations)
I was trying out django-extensions yesterday, when it all got messed up after me running some direct SQL queries and I reset hard using git. I'm still learning about migrations, so I don't understand what is wrong, since it seems to me that both migrations already have been applied.
Thank you for your help!
This worked for me. I thank my coworker for sharing this knowledge after I searched online for many hours.
Start your db shell
python manage.py dbshell
Use the database you want. If you don't know, run .databases (SQLite) or SHOW databases
mysql>use <database_name>;
Retrieve all the migrations under your app
mysql> select * from django_migrations where app='<app>';
You will see the output with ids next to all migrations. Look at the migration you want to drop. Say the id is 361
mysql> delete from django_migrations where id=361;
You have squashed the migrations, so one of the dependencies that 0016_auto_<date2>_<time2> had is now part of the newly created squashed migrations. Meanwhile the 0016_auto_<date2>_<time2> has already been run and now you're trying to run the squashed migration.
I personally don't know if there's any way to fix this automatically. You will need to fix the issues yourself. If you have version control, revert these changes and try to rethink how you should squash the migration without affecting old ones.
I have solved this problem when i did (custom user model) by this steps:
delete this file :
migrations\0001_initial.py
delete this :
db.sqlite3
put this code in settings.py :
AUTH_USER_MODEL = 'users.CustomUser'
Then do (makemigrations) then (migrate )
run server .. the problem solved :)
i have used this link it is help me to solve the problem of dependency :
https://docs.djangoproject.com/en/3.1/topics/auth/customizing/
Due to limitations of Django’s dynamic dependency feature for swappable models, the model referenced by AUTH_USER_MODEL must be created in the first migration of its app (usually called 0001_initial); otherwise, you’ll have dependency issues.
In addition, you may run into a CircularDependencyError when running your migrations as Django won’t be able to automatically break the dependency loop due to the dynamic dependency. If you see this error, you should break the loop by moving the models depended on by your user model into a second migration. (You can try making two normal models that have a ForeignKey to each other and seeing how makemigrations resolves that circular dependency if you want to see how it’s usually done.)
run this python manage.py dbshell
INSERT INTO public.django_migrations(app, name, applied)
VALUES ('YOUR_APP_NAME, '0017_<modelname>_squashed_0019_auto_<date3>_<time3>', now());
and you should be fine. If Your migration was changing a lot to the database, then I am afraid it won't be that easy to fix it.
you need to fake migrations and migrate again
just make sure that you have a backup from your data because when you migrate again you need to delete apps table.
make sure that you look at show migrations and migrate un migrated apps by its sequence
Edit the dependencies of the conflicting migration, so that it no longer references the already applied migration.
Then run python manage.py migrate again and it should be fixed.
Warning: this only work suppossing that the state of the database matchs the state you get having applied the conflicting migration.
I had the same issue on 2020 with Django 3.0.6.
I tried all the relevant answers with no success. So I went in my database and deleted all the tables. You must export the relevant tables if you have done lot of work. I mainly delete django files in my database. And after, run:
python manage.py makemigrations <my-app>
And:
python manage.py migrate
Export your relevant tables if any.
First back up your database before resolving the conflicts, (Use "python manage.py dumpdata > db.json" for SQLite).
Execute python manage.py dbshell, to access the database.
Delete the migrations rows that are having conflicts from the django_migrations table.
Rename the tables conflicting in the database
Execute the makemigrations and migrate commands
After successful migrations, Drop the newly readded tables and finally restore the previously renamed tables to match the migrations need
I had the same problem, and here's how I solved it.
The following is my error message
File "/usr/local/lib/python3.11/site-packages/django/db/migrations/loader.py", line 327, in check_consistent_history
raise InconsistentMigrationHistory(
django.db.migrations.exceptions.InconsistentMigrationHistory: Migration aaaa.0024_campaign_template is applied before its dependency bbbb.0005_templatemodel_from_template on database 'default'.
My solution
python manage.py migrate bbbb
python manage.py migrate
Because I changed the Django's app name in batches, the application order was not consistent when applied to the database. The bbbb that aaaa relies on was not created first, so I manually created the bbbb first
Migration file is not created for all app:
step 1:
create migration folder and add __init__.py file for all app
step 2:
delete db.sqlite3 database
step 3:
python manage.py migrate
python manage.py makemigrations
Delete all of your migrations folder
Delete the database(sqlite3)
Then run the makemigrations and migrate command
Delete the migration files.
Run:
python manage.py migrate
python manage.py makemigrations
python manage.py migrate
python manage.pyrunserver

Django 1.8: Create initial migrations for existing schema

I started a django 1.8 project, which uses the migrations system.
Somehow along the way things got messy, so I erased the migrations folders and table from the DB, and now I'm trying to reconstruct them, with no success.
I have three apps (3 models.py files), and the models reflect the tables EXACTLY!
The best approach that I've found so far was:
Erase all migrations folders. Done!
Delete everything from the django_migrations table. Done!
Run python manage.py makemigrations --empty <app> for every app. Done!
Run python manage.py migrate --fake. Done! (although it works only if I run it after every makemigrations command.
Now I add a new field, run the makemigrations command, and I receive the following error:
django.db.utils.OperationalError: (1054, "Unknown column 'accounts_plan.max_item_size' in 'field list'")
I've been burning HOURS on this thing. How the h**l can I initialize the migrations so I can continue working without migration interruptions every time?
Why is it so complicated? Why isn't there a simple one-liner: initiate_migrations_from_schema?
EDIT:
Now things get even nastier. I truncated the django_migrations table and deleted all the migrations folder.
Now I try to run python manage.py migrate --fake-initial (something I found in the DEV docs), just so it sets up all of Django's 'internal' apps (auth, session, etc) and I'm getting:
(1054, "Unknown column 'name' in 'django_content_type'").
Now, this "column" is not a real column. It's a #property defined in Django's contenttypes app. WHAT IS GOING ON HERE? Why is it identifying the name property as a real column?
Finally got it to work, although I don't know why and I hope it will work in the future.
After doing numerous trials and going through Django's dev site (link).
Here are the steps (for whoever runs into this problem):
Empty the django_migrations table: delete from django_migrations;
For every app, delete its migrations folder: rm -rf <app>/migrations/
Reset the migrations for the "built-in" apps: python manage.py migrate --fake
For each app run: python manage.py makemigrations <app>. Take care of dependencies (models with ForeignKey's should run after their parent model).
Finally: python manage.py migrate --fake-initial
After that I ran the last command without the --fake-initial flag, just to make sure.
Now everything works and I can use the migrations system normally.
I'm sure I'm not the only one who encounters this issue. It must be documented better and even simplified.
Update for Django 1.9 users:
I had this scenario again with a Django 1.9.4, and step 5 failed.
All I had to do is replace --fake-initial with --fake to make it work.
django ..., 1.8, 1.9, ...
What you want to achieve is squashing existing migrations and use replacement for them.
How to do it right without using any command when releasing (a case without impact on database and coworkers).
For every app, get rid of its migrations folder:
mv <app>/migrations/ <app>/migrationsOLD/
For each that app run: python manage.py makemigrations <app>.
Customize each new migration:
if you have a complex app, or more apps and related models between them, to avoid CircularDependencyError or ValueError: Unhandled pending operations for models:
prepare second empty migration in <app> 0002_initial2.py (put there dependency to app_other::0001_initial.py and <app>::0001_initial.py as well - all ForeignKey, M2M related to models created in 0001 migration step in other apps)
All must be in order - sometimes it will require more migrations to prepare. Take care of dependencies attribute here in each Migration.
take care of initial values - verify yourself all RunPython actions from migrationsOLD and copy the code to new initial migration if needed.
(optional for --fake-initial) Add initial=True to all new Migration classes (0002 too if was added).
Add replaces attribute in new Migration class. (like own custom a squashmigrations). Put there all old migrations from <app>
Verify everything with makemigrations.
assert "No changes detected"
Check if migrate -l show [x] everywhere
assert similar:
[X] 0001_initial
[X] 0002_initial2 (102 squashed migrations)
Example:
For old:
0001_initial.py
0002_auto.py
...
0103_auto.py
prepare:
0001_initial.py
0002_initial2.py (optional but sometimes required to satisfy dependency)
and add to replacesto last one (0002 here, can be 0001):
replaces = [(b'<app>', '0002_auto.py'), ..., (b'<app>', '0103_auto.py')]
0001_initial.py should be named the same way as old one.
0002_initial2.py is new one, but it's a replacement for old migrations so Django will treat it as loaded.
I've run into this scenario but I've never had to drop the database to solve it. Typically I delete the migrations folder from the app's, and remove the migration entries from the database.
I would try to run make migrations one app at a time. If any of the app's rely upon other tables obviously add them last.
Also I usually just run, python manage.py makemigrations then just python manage.py migrate Even with the initial migration it should work fine with Django 1.7 and 1.8.
If you are using routers, might be a problem there. Check method allow_migrate if it is executed in a right way in routers.py. Try to set return value always to be True, and check whether it resolves problem,
def allow_migrate(self, db, app_label, model_name=None, **hints):
return True

Django South - table already exists

I am trying to get started with South. I had an existing database and I added South (syncdb, schemamigration --initial).
Then, I updated models.py to add a field and ran ./manage.py schemamigration myapp --auto. It seemed to find the field and said I could apply this with ./manage.py migrate myapp. But, doing that gave the error:
django.db.utils.DatabaseError: table "myapp_tablename" already exists
tablename is the first table listed in models.py.
I am running Django 1.2, South 0.7
since you already have the tables created in the database, you just need to run the initial migration as fake
./manage.py migrate myapp --fake
make sure that the schema of models is same as schema of tables in database.
Although the table "myapp_tablename" already exists error stop raising
after I did ./manage.py migrate myapp --fake, the DatabaseError shows
no such column: myapp_mymodel.added_field.
Got exactly the same problem!
1.Firstly check the migration number which is causing this. Lets assume it is: 0010.
2.You need to:
./manage.py schemamigration myapp --add-field MyModel.added_field
./manage.py migrate myapp
if there is more than one field missing you have to repeat it for each field.
3.Now you land with a bunch of new migrations so remove their files from myapp/migrations (0011 and further if you needed to add multiple fields).
4.Run this:
./manage.py migrate myapp 0010
Now try ./manage.py migrate myapp
If it doesn't fail you're ready. Just doublecheck if any field's aren't missing.
EDIT:
This problem can also occur when you have a production database for which you install South and the first, initial migration created in other enviorment duplicates what you already have in your db. The solution is much easier here:
Fake the first migration:
./manage migrate myapp 0001 --fake
Roll with the rest of migrations:
./manage migrate myapp
When I ran into this error, it had a different cause.
In my case South had somehow left in my DB a temporary empty table, which is used in _remake_table(). Probably I had aborted a migration in a way I shouldn't have. In any case, each subsequent new migration, when it called _remake_table(), was throwing the error sqlite3.pypysqlite2.dbapi2.OperationalError: table "_south_new_myapp_mymodel" already exists, because it did already exist and wasn't supposed to be there.
The _south_new bit looked odd to me, so I browsed my DB, saw the table _south_new_myapp_mymodel, scratched my head, looked at South's source, decided it was junk, dropped the table, and all was well.
If you have problems with your models not matching your database, like #pielgrzym, and you want to automatically migrate the database to match the latest models.py file (and erase any data that won't be recreated by fixtures during migrate):
manage.py schemamigration myapp --initial
manage.py migrate myapp --fake
manage.py migrate myapp zero
manage.py migrate myapp
This will only delete and recreate database tables that exist in your latest models.py file, so you may have garbage tables in your database from previous syncdbs or migrates. To get rid of those, precede all these migrations with:
manage.py sqlclear myapp | manage.py sqlshell
And if that still leaves some CRUFT lying around in your database then you'll have to do an inspectdb and create the models.py file from that (for the tables and app that you want to clear) before doing the sqlclear and then restore your original models.py before creating the --initial migration and migrating to it. All this to avoid messing around with the particular flavor of SQL that your database needs.
Perform these steps in order may help you:
1) python manage.py schemamigration apps.appname --initial
Above step creates migration folder as default.
2) python manage.py migrate apps.appname --fake
generates a fake migration.
3) python manage.py schemamigration apps.appname --auto
Then you can add fields as you wish and perform the above command.
4) python manage.py migrate apps.appname
If you have an existing database and app you can use the south conversion command
./manage.py convert_to_south myapp
This has to be applied before you do any changes to what is already in the database.
The convert_to_south command only works entirely on the first machine you run it on. Once you’ve committed the initial migrations it made into your VCS, you’ll have to run ./manage.py migrate myapp 0001 --fake on every machine that has a copy of the codebase (make sure they were up-to-date with models and schema first).
ref: http://south.readthedocs.org/en/latest/convertinganapp.html
As temporary solution, you can comment the Table creation in the migration script.
class Migration(migrations.Migration):
dependencies = [
(...)
]
operations = [
#migrations.CreateModel(
# name='TABLE',
# fields=[
# ....
# ....
# ],
#),
....
....
Or
If the existing table contains no rows (empty), then consider deleting the table like below. (This fix is recommended only if the table contains no rows). Also make sure this operation before the createModel operation.
class Migration(migrations.Migration):
dependencies = [
(...),
]
operations = [
migrations.RunSQL("DROP TABLE myapp_tablename;")
]
One more solution(maybe a temporary solution).
$ python manage.py sqlmigrate APP_NAME MIGRATION_NAME
eg.,.
$ python manage.py sqlmigrate users 0029_auto_20170310_1117
This will list all the migrations in raw sql queries. You can pick the queries which you want to run avoiding the part which creates the existing table