Django on Heroku: relation does not exist - python

I built a Django 1.9 project locally with sqlite3 as my default database. I have an application named Download which defines the DownloadedSongs table in models.py:
models.py
from __future__ import unicode_literals
from django.db import models
class DownloadedSongs(models.Model):
song_name = models.CharField(max_length = 255)
song_artist = models.CharField(max_length = 255)
def __str__(self):
return self.song_name + ' - ' + self.song_artist
Now, in order to deploy my local project to Heroku, I added the following lines at the bottom of my settings.py file:
import dj_database_url
DATABASES['default'] = dj_database_url.config()
My application has a form with a couple of text fields, and on submitting that form, the data gets inserted into the DownloadedSongs table. Now, when I deployed my project on Heroku and tried submitting this form, I got the following error:
Exception Type: ProgrammingError at /download/
Exception Value: relation "Download_downloadedsongs" does not exist
LINE 1: INSERT INTO "Download_downloadedsongs" ("song_name", "song_a...
This is how my requirements.txt file looks like:
beautifulsoup4==4.4.1
cssselect==0.9.1
dj-database-url==0.4.1
dj-static==0.0.6
Django==1.9
django-toolbelt==0.0.1
gunicorn==19.6.0
lxml==3.6.0
psycopg2==2.6.1
requests==2.10.0
static3==0.7.0
Also, I did try to run the following commands as well:
heroku run python manage.py makemigrations
heroku run python manage.py migrate
However, the issue still persists. What seems to be wrong here?

Make sure your local migration folder and content is under git version control.
If not, add, commit & push them as follows (assuming you have a migrations folder under <myapp>, and your git remote is called 'heroku'):
git add <myapp>/migrations/*
git commit -m "Fix Heroku deployment"
git push heroku
Wait until the push is successful and you get the local prompt back.
Then log in to heroku and there execute migrate.
To do this in one execution environment, do not launch these as individual heroku commands, but launch a bash shell and execute both commands in there: (do not type the '~$', this represents the Heroku prompt)
heroku run bash
~$ ./manage.py migrate
~$ exit

You must not run makemigrations via heroku run. You must run it locally, and commit the result to git. Then you can deploy that code and run those generated migrations via heroku run python manage.py migrate.
The reason is that heroku run spins up a new dyno each time, with a new filesystem, so any migrations generated in the first command are lost by the time the second command runs. But in any case, migrations are part of your code, and must be in version control.

As Heroku's dynos don't have a filesystem that persists across deploys, a file-based database like SQLite3 isn't going to be suitable. It's a great DB for development/quick prototypes, though. https://stackoverflow.com/a/31395988/784648
So between deploys your entire SQLite database is going to be wiped, you should move onto a dedicated database when you deploy to heroku I think. I know heroku has a free tier for postgres databases which I'd recommend if you just want to test deployment to heroku.

python manage.py makemigrations
python manage.py migrate
python manage.py migrate --run-syncdb
this worked for me.

I know this is old, but I had this issue and found this thread useful.
To sum up, the error can also appear when executing the migrations (which is supposed to create the needed relations in the DB), because recent versions of Django check your urls.py before doing the migrations. In my case - and in many others' it seems, loading urls.py meant loading the views, and some views were class-based and had an attribute defined through get_object_or_404:
class CustomView(ParentCustomView):
phase = get_object_or_404(Phase, code='C')
This is what was evaluated before the migrations actually ran, and caused the error. I fixed it by turning my view's attribute as a property:
class CustomView(ParentCustomView):
#property
def phase(self):
return get_object_or_404(Phase, code='C')
You'll know quite easily if this is the problem you are encountering, as the Traceback will point you towards the problematic view.
Also this problem might not appear in development because you have migrated before creating the view.

Related

Heroku No migrations to apply

I'm having trouble with my database at Heroku:
I've added some models for my App and whenever I run makemigrations it detects those changes. However when I run migrate it only says no migrations to apply. Please help!
I'VE FINALLY FIXED IT!!! This is what I did:
First I did a backup Download by heroku pg:backups:restore capture
then heroku pg:backups:restore download
it made a "latest.dump" file
then I used heroku pg:reset
it deleted the recent database of host
then I applied my fixes on my models and forms
new fields has to have "defaults=None" for models with Data you want to preserve (If you won't do this, the merge for this model won't take effect and will be cancelled)
then I run heroku run bash
run python manage.py makemigrations appname
then migrate
and then used "pg_restore --verbose --clean --no-acl --no-owner -h yourDBhost -U yourDBuser -d yourDBname latest.dump" (Your database credentials will be found on your postgresql addon settings) and then type or copy-paste yourDBpassword(from credentials also) to merge the backed up database with the new one with changes
and know it's done and perfectly working!

Relation does not exist error in Django

I know there are many questions about this problem, I looked through the solutions and unfortunately none of them worked for me.
I created a new app called "usermanagement", and added a model to the app. After adding the model I added usermanagement to INSTALLED_APPS in settings. Then I ran python manage.py makemigrations, and python manage.py migrate. This all worked fine! I also did try running the migrations with the app-name.
The problems start when I try to add a new instance of the model to the database in the Python-Django shell, by using:
>>>a = ClubOfficial(name="randomName", email="randomemail#random.com")
>>>a.save()
I get the following error:
django.db.utils.ProgrammingError: relation
"usermanagement_clubofficial" does not exist
LINE 1: INSERT INTO "usermanagement_clubofficial" ("name", "email") ...
Below is the model code:
class ClubOfficial(models.Model):
name = models.CharField(max_length=254)
email = models.EmailField(max_length=254)
If it helps, I use postgresql, and have tried restarting the server. The other apps in the program also work perfectly fine, it is just usermanagemenet that has this problem.
Does anyone know what could be going wrong?
Thank you for your time!
Note: I created a new app now with a different name, copy-pasted things from usermanagement and everything worked fine. I think the problem might be that before there was an app named usermanagement which was deleted, before I created it again. Maybe that messed up the database somehow.
TL;DR: Make sure your app's migrations folder has an __init__.py file. If it isn't there, create it again as an empty file.
I ran into this. In my case I had a previously working django app, not yet moved to production, so I deleted everything in my app's migrations folder, then using django extensions I wiped the postgresql database and cached files with:
./manage.py clear_cache
./manage.py clean_pyc
./manage.py reset_schema
./manage.py reset_db
# then deleted all files (including __init__.py) from my app's migrations folder.
I verified that my postgresql database had no tables. I then ran:
./manage.py makemigrations
./manage.py migrate
Which gave the output:
No changes detected
./manage.py migrate
Operations to perform:
Apply all migrations: admin, auth, contenttypes, sessions
Running migrations:
Applying contenttypes.0001_initial... OK
(about 11 more lines of output here which are similar)
It is notable that my model's names where nowhere in the migration. I printed the tables in my postgresql database and the Widget and Section tables were both missing. Running the app gave me this error (I substituted 'app' and 'model' for their real names):
ProgrammingError at /my_path
relation "app_model" does not exist
LINE 1: ..."."my_field", "app_model"."my_field" FROM "appname...
So the tables for the models were not being created in the database. My app's migrations folder was also completely empty. The solution was to just add an empty __init__.py to my app's migrations folder, and after that running makemigrations was able to create and save the migration file in the folder. This could then be executed with migrate. You can test this for yourself by running makemigrations with and without the __init__.py in the migrations/ folder.
This solution was not mine but one given by user Ljubitel on another post but it was not the accepted answer there, but the accepted answer didn't work for me so I wrote this solution here to hopefully help others.
I had this same problem, but all I had to do was run
$ python manage.py makemigrations
and
$ python manage.py migrate
In case you have deleted your migration folder.
Create a folder called migration in whatever app name you have created and then create a file in the migration folder called __init__.py
In my case I was pointing to a different databases between my local server and the production server. The database that the production server was pointing to was a few versions behind, so the server could not locate the relation. If your issue were localized to one environment, check the configs first.
Another method to fix relation does not exist error
Create same table in db(postgre, mysql) using sql query tool
now comment your model in models.py and admin.py
run migration using :
python manage.py makemigrations app_name
python manage.py migrate
now uncomment and run migrations command again
I encountered same issue and fixed using following method, I am using postgres(pgadmin 4).

Reinstalling Django App - Data tables not re-created

I am trying to reinstall one of my apps on my project site. These are the steps that I have followed to do so:
Removing the name of the installed app from settings.py
Manually deleting the app folder from the project folder
Manually removing the data tables from PostgreSQL
Copying the app folder back into the project folder; making sure that all files, except __init__.py is removed.
Run python manage.py sqlmigrate app_name 0001
Run python manage.py makemigrations app_name
Run python manage.py migrate app_name
Run python manage.py makemigrations
Run python manage.py migrate
However, after all these steps the message I am getting is that there are "no changes detected" and the data tables have not been recreated in the database, PostgreSQL.
Am I missing some additional steps?
I think I might have managed to solve the problem. The command, python manage.py sqlmigrate app_name 0001, produces the SQL statements required for the table creation. Thus, I copied and paste the output into the PostgreSQL console and got the tables created. It seems to work for now, but I am not sure if there will be repercussions later.

Django : Table doesn't exist

I dropped some table related to an app. and again tried the syncdb command
python manage.py syncdb
It shows error like
django.db.utils.ProgrammingError: (1146, "Table 'someapp.feed' doesn't exist")
models.py
class feed(models.Model):
user = models.ForeignKey(User,null=True,blank=True)
feed_text = models.CharField(max_length=2000)
date = models.CharField(max_length=30)
upvote = models.IntegerField(default=0)
downvote = models.IntegerField(default=0)
def __str__(self):
return feed.content
What I can do to get the tables for that app ?
drop tables (you already did),
comment-out the model in model.py,
and ..
if django version >= 1.7:
python manage.py makemigrations
python manage.py migrate --fake
else
python manage.py schemamigration someapp --auto
python manage.py migrate someapp --fake
comment-in your model in models.py
go to step 3. BUT this time without --fake
For those that may still be having trouble (like me), try this out:
Comment out all the URL's in the main app's urls.py
Then go ahead and run migrations:
$ ./manage.py makemigrations
$ ./manage.py migrate
The problem was alleviated by removing the ()'s
solved_time = models.DateTimeField('solved time', default=timezone.now())
to
solved_time = models.DateTimeField('solved time', default=timezone.now)
I got this answer from reddit
What solved my problem in situation when manage.py setmigration and then migrate to the SQL database is not working properly did is following:
Run command : python manage.py migrate --fake MyApp zero
After that: python manage.py migrate MyApp
And the problem that rises with connections.py and and after running correctly the migration command is solved! At least for me.
I'm using Python (3.x), MySQL DB, Django (3.x), and I was in situation when I needed after some time of successfully creating tables in my database, that some error regarding connections.py raises. But, above commands helped. I hope they will help all those who are having these type of problems.
I just ran migrations with the name of the app attached, for all the apps I had provisioned and that worked.
e.g. python3 manage.py makemigrations my_custom_app
After running for all of them I ran a migrate command to seal the deal.
python3 manage.py migrate. That was it. I'm still wondering why django behaves this way sometimes though.
none of the above solutions worked for me, I finally solved by
sudo systemctl stop mysql.service
sudo apt-get purge mysql-server
sudo apt-get install mysql-server
sudo systemctl stop mysql.service
In my case the code that I pulled had managed = False and I wanted the tables to be maintained by Django.
But when I did makemigrations the custom tables were not being detected or I was getting the error that the app_name.Table_name does not exist
I tried the following:
delete all the migration files inside the migrations folder (except init.py file) and then makemigrations then finally migrate
above 2 answers
this
PS: This solution is only feasible if backup is present or data is not important or you are just started creating the tables, as purging mysql will lead to loss of data
This is linked to the migration data in the scripts inside the project not matching with the migration scripts in the database as far as I could tell.
I solved this by the following steps :
Delete all the migration scripts under migration folder except __ini__
Make sure that the model.py contains the same structure as the table in the database and managed=True
Remove all Django Created tables like auth_user,... etc
Run the following code
$ ./manage.py makemigrations
$ ./manage.py migrate
This will create the migration scripts again and will apply it to your database.
I had this issue where I was playing with same database structure in production vs development. While dropping and recreating tables will probably resolve the issue, its worth checking your database itself and see if the model is actually correct. For myself I created the development database incorrectly with the table names all in lowercase while in production the first letter of tables were capitalized. I used the python manage.py inspectdb command on production db, and compared it to the model and realized that in the model it was trying to insert data to table 'test' instead of 'Test' for example. Hope that helps some of you in future.
I had a similar issue.
I had another python (with a class) file which need access to DB.
For some reasons, when running 'makemigrations' this file was processed (I guess this is linked to some import chains).
In this class, I had a method containing a default arg method(defaultModel=Model.get_default()) in the signature which was accessing to the default object in the DB (static method included in the Model class).
A the import time, this default arg was evaluated and as the table is not populated yet, it gives this error.
So I just set None for the default args and asks for the default model object inside the method. This solved the issue.
I have to face same issue and there are a couple of approaches, but the one I think is the most probable one.
Maybe you are loading views or queries to database but you havenĀ“t granted enough time for Django to migrate the models to DB. That's why the "table doesn't exist".
Make sure you use this sort of initialization in you view's code:
Class RegisterForm(forms.Form):
def __init__(self, *args, **kwargs):
super(RegisterForm, self).__init__(*args, **kwargs)
A second approach is you clean previous migrations, delete the database and start over the migration process.
I tried all of the above tricks and never worked for me.
I commented on all imports and URLs that called a particular Table
In this solution, your data will be removed. I removed the app and created the app again. I copied the app folder somewhere and delete the app folder from my project. I commented on all lines in urls.py and files similar views.py and admin.py that use this app. also app name in settings.py.
In mysql:
truncate django_migrations;
truncate django_admin_log;
Do this for all models in your app and change n.
n is app id.
delete from auth_permission where content_type_id=n
delete from django_content_type where app_label='appname'
python manage.py startapp your_app_name
Then uncomment previous lines and restore files and run
python manage.py makemigrations
python manage.pt migrate
I faced the same problem, some of the above mentioned answers seemed not to work for me, but here's a simple 4 step solution:
1) Delete the migrations files below __init__.py (don't delete __init__.py) in your specific app.
2) python manage.py makemigrations AppName
3) python manage.py migrate --fake AppName zero
4) python manage.py migrate AppName
Hope these works for you.
I faced the same issue earlier when I accidentally deleted my migrations folder in an app. I was able to fix it by running manual makemigrations for that specific app.
Here's the fix for Windows,
py manage.py makemigrations <your_app_name>
py manage.py migrate
For other OS you need to replace py with python3 or python
I hope this helped fix your issue!
if the python manage.py migrate still doesn't work I mean when you do this it nothing do anything you can delete the app's migrations from django_migrations table after then do
python manage.py migrate

Syncdb - "DatabaseError: no such table: django_site"

So i clone my repo, sourced it, ran pip on its dependencies and synced my db only the sync fails with:
DatabaseError: no such table: django_site
I checked the path vars in settings.py and it's pointing to my website root, in fact it even creates the db file specified in settings.py db.sqlite3 in the root when I run sync. If the path is correct and django can create the db file, why can't it populate it? What am I missing here ?
EDIT: I have tried commenting out "django.contrib.sites" from my installed apps and running manage.py migrate and migrate sites, I still get the same error and an empty database file.
Give a full traceback and your INSTALLED_APPS, please.
I had the same issue when installing both django-cms and django-debug-toolbar. The problem was in toolbar, so I solved it by deactivating toolbar for suncdb.

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