seed.md

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Seeding

Seed scripts are used to populate the database with dummy data for testing. Seed scripts are located in root/management/commands/seed_scripts/.

Seeding locally

To seed the database locally, run this in terminal:

• python manage.py seed

To seed specific tables (eg. events), use a name parameter:

• python manage.py seed <name>

For instance, to seed events run:

• python manage.py seed events

Seeding in docker

After docker container is running:

• 1. Open shell in Docker container: docker compose exec backend bash
• 2. Enable poetry: poetry shell
• 3. Run seed script: python manage.py seed

Adding/changing seed scripts

The seed script seed.py does not need to be modified to add new seed scripts. Instead, add scripts inside the seed_scripts/ folder. In order for them to be detected, you must include it in the seed_scripts/__init__.py file:

from . import your_seed_script

SEED_SCRIPTS = [
    # ... 
    ('your_name', your_seed_script.your_function) # Add here
]

Seed scripts only have to have a single function (set in the SEED_SCRIPTS list), but could be as complex as you want. A typical seed script will look like this:

COUNT = 10

def seed():

    # It is good practise to delete old objects to prevent lots of duplicates
    SomeObject.objects.all().delete()
    yield 0, 'Deleted old stuff'

    # Loop for some number of steps
    for i in range(COUNT):

        # Create object
        SomeObject.objects.create(
            something=i,
            # ... other fields
        )

        # Yield progress (number between 1-100) and a descriptive string. 
        # Used for pretty loading indicators.
        yield i / COUNT, f"Created some object '{i}'"

    # Done! Yield 100 to show a finished loading bar, and a final description
    yield 100, f'Created {len(Venue.objects.all())} venues'

Checkout python generators to see how yield works. In short, the function basically works as a list that is computed in real time, so inside seed.py the script "loops through" the seed function and prints progress over time. Good luck!