I am running a GIS application while getting this error. I have attached error snapshot . Can Someone guide where is error ? If need to see code . Let me know which file you need.
Especially the first line of your exception value pretty much says it all.
Column users.parent_id does not exist
The application is trying to access parent.id from the users table from your database, which obviously does not exist. With other words, your database is not sync with the model structure in the source code. Probably all you have to do, is to run the migrations to add all the missing structures or changes to your database.
If you've developed some of the database structures yourself, you have to run the makemigrations command to build the new migration set for your database.
./manage.py makemigrations
If you have created new migration files or if you have installed and integrated modules into your app, you have to apply the migrations to your database.
./manage.py migrations
Related
I have a Postgres database full of data. And I made several changes to my Django app models.
mange.py makemigrations worked fine and created the migration files. But manage.py migrate execute only one file. And when I launch it again it doesn’t execute the rest as if they are already applied.
I deleted the migration files that were not applied and did another makemigration but it says no changes detected.
Any ideas how to reflect the models changes on the database without losing the data ?
Thanks
Django keeps track of which migrations it has applied already, so when you run the migrate command it will execute only the migrations that Django thinks that are missing.
I deleted the migration files that were not applied and did another makemigration but it says no changes detected.
This was a bad idea, it will make your migrations inconsistent.
If you want to go back in time, instead of deleting migrations, the proper way to do this is by reverting migrations. You can use the same migrate command and specify to which migration point you want your database model to be.
Check this answer for further information about reverting migrations; django revert last migration
I have an app that I recently did a migration for that included adding a new table. I can see that the migration worked, the table is populated, I can access it, etc. Even when I run
python manage.py migrate my_app -l
I can see the migration as having been successfully run.
However when I run my unit tests I get:
OperationalError: no such table: my_app_my_table
The only thing I can thing of is that the in memory database is not running all the migrations? Or it's not doing it correctly? Any help would be greatly appreciated.
It could be the case that your migrations aren't actually generating the SQL code you intended, and it's probably worth running sqlmigrate on the specific migrations to make sure it's generating code to make the table.
If the SQL code looks right, something weird could have happened and django thinks you ran the migration but it didn't actually change the database. In that case, you could try restoring an older version of the database and running the migrations on that?
Actually we are group of 3 people working on the same project, and each one individually make changes in django database. After running migrations in individual machine, it creates migration file for each migration. When someone pushes updated code in remote git repository, it creates conflict with others' migrations of same name.
Because of this reason, I lost my whole data once. Kindly give suggestions what should I do with this migration thing?
here's what i do: whenever I want to fetch from remote i check if a duplicate migration will be fetched. (we have a script that checks for all migration directories if there are filenames which have the same starting number.) if that is the case, I 'merge' the migrations, usually like this:
Find the last migration before the duplicate, let's say it's migration 000X
Make sure you are on your local source version, before the duplicate is added.
migrate back to after migration n:
python manage migrate app 000X
pull the new version including the duplicates.
remove your duplicate migrations
run schemamigration
python manage schemamigration --auto
Now you should get a new migration adding your model changes on top of the changes that were made in the migration you pulled.
One of our clients needs to add some geolocation data to their
site. Since they already have a database setup without GIS extensions,
I decided to create a new database (with the GIS extensions), which I
intend to use to store only the geolocation data.
I had, at some point, set things up to work alright on my development
machine (meaning, I have migrations for these new models). But now that the code has been written, I imported a DB dump
directly from the server so that my development machine exactly
mirrors the production machine, and now I can't seem to get South to
apply the migrations correctly. South seems to have several features
which allow for multiple databases, but none of them have worked so far.
What I've tried:
Just adding the model and migrating. This gives me the following
error:
AttributeError: 'DatabaseOperations' object has no attribute
'geo_db_type'
OK, so South is trying to create the model on the original database
which doesn't have the GIS extensions.
Adding the model, but specifying the 'geo' database for migrating
the 'geo' app. This gives me the following error:
django.db.utils.DatabaseError: relation "south_migrationhistory"
does not exist
I guess south expects its MigrationHistory table to exist on the 'geo'
database as well?
Allow south's models to exist on my 'geo' database.
$ python manage.py syncdb --database=geo
$ python manage.py migrate
This gives me the following error:
django.db.utils.DatabaseError: relation "<model>" already exists
I'm guessing this is because I already have MigrationHistories stored
in the other database?
South apparently has a sparsely documented feature called 'dbs'
(see:
http://south.aeracode.org/docs/databaseapi.html#accessing-the-api )
So I tried the previous three methods again replacing all instances of
"db" with "dbs['geo']".
a. Migrations run smoothly, but don't actually create any tables
in my 'geo' database.
b. Same error as when not using 'dbs' features.
c. Same error as when not using 'dbs' features.
This entire process has been extremely frustrating. Has anyone got
multiple database support up-and-running when using South?
Whenever I have modified the table models I used south and these commands to modify the structure and they always worked:
python manage.py convert_to_south "your_app"
python manage.py migrate "your_app"
I recommend running these commands after running syncdb, so your tables are created.
I'm using sqlite3 and pycharm to learn more about django, and googled to find that south is recommended to make it easier to modify models after they have been created.
I'm trying to follow the advice on http://south.aeracode.org/docs/tutorial/part1.html#starting-off.
The most success I've had so far is to create a simple model and run syncdb before adding south to installed_apps. That way the intial tables are created and I get a chance to create a super user. (Django admin seems to fret if there are no users).
Then I add south to installed_apps, and run django_manage.py schemamigration bookmarks --initial
It seems to work fine. A new directory is created called migrations with a couple of files in it in my app folder and an encouraging message.
"Created 0001_initial.py. You can now apply this migration with: ./manage.py migrate bookmarks"
The next step - django_manage.py" migrate bookmarks generates the following error message
django.db.utils.DatabaseError: no such table: south_migrationhistory.
I thought that table would be created in the first schememigration step. What am I missing? Can anyone help?
Marg
South uses a table if its own to keep track of which migrations have been applied. Before you can apply any migrations, this must have been created, using python ./manage.py syncdb.
As well as for setting up south, you will find syncdb sometimes necessary for non-south apps in your project, such as the very common django.contrib.auth.
Note that as a convenience, you can run both in one go like this
python ./manage.py syncdb --migrate
My latest (unsuccessful) effort was the following
Create application – synch db – superuser created
Test run –admin screen shows basic tables
Add south, and syncdb from command line with manage.py syncdb – south_migrationhistory table created. Add basic vanilla model
Tried various combinations of manage.py syncdb –manage, and
schemamigration from Pycharm (if run from within pycharm a
migrations directory is created within the app
– if run from the command line the directory does not seem to be
created.)
Django admin screen shows table – but if I try to edit
the table it says that it doesn’t exist
Check database structure
using SQLite browser - table for newly created model doesn’t exist
I’m starting to think that the whole thing is not worth the time wasting hassle – maybe I’m better off just modifying the tables in SQLite browser
Answer in the similar question:
Run syncdb to add the Django and South tables to the database.