Django has a nice way to do this the choices parameter for ChoiceField can either be an iterable object like a list, or it can be a function that returns an iterable object. The solution is to defer the getting of the list of Foo objects until it's actually needed - that is, until you create an instance of the form, rather than when you define it. But that depends on the existence of the Foo model in the database so at import time, before the migrations have been run, it will run the (), which means that it will try to connect to the DB and read in the appropriate values - which will fail because it hasn't got to running the migrations yet so there is no table for Foo in the DB. Part of the code that it imports is the definition of the BarForm. When Django starts up in order to run your migrations, it imports all of your code as a first step. But if you're starting with a fresh database, and want to run a migration to get it all set up, you have a problem. This will work fine if you already have the Foo object set up and populated when you add the form to your code. Ticket tracker Report bugs with Django or Django documentation in our ticket tracker.Class BarForm ( forms. Official Django Forum Join the community on the Django Forum. Django Discord Server Join the Django Discord Community. In this section, we will learn to connect SQLite databases, create table objects, and use them to run the SQL query. It was created in the mytennisclub root folder, and has the filename db.sqlite3. #django IRC channel Ask a question in the #django IRC channel, or search the IRC logs to see if it’s been asked before. When we created the Django project, we got an empty SQLite database. To be able to use PostgreSQL in Django we. We will add a PostgreSQL database to our Django project. It has a good reputation, it is reliable, and it perform well under most circumstances. django-users mailing list Search for information in the archives of the django-users mailing list, or post a question. PostgreSQL database is an open source relational database, which should cover most demands you have when creating a database for a Django project. Index, Module Index, or Table of Contents Handy when looking for specific information. When a database is accessed by multiple connections, and one of the processes modifies the database, the SQLite database is locked until that transaction is committed. If database is opened successfully, it returns a connection object. Getting help FAQ Try the FAQ - it's got answers to many common questions. You can use ':memory:' to open a database connection to a database that resides in RAM instead of on disk.
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