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Documentation Index

Fetch the complete documentation index at: https://docs.backant.io/llms.txt

Use this file to discover all available pages before exploring further.

BackAnt includes Alembic (alembic~=1.12.0) in requirements.txt for database migrations.

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How tables are created

In development, BackAnt takes a code-first approach: Base.metadata.create_all(engine) in init_db() creates any tables that don’t yet exist on every startup. This means for new routes, you don’t need a migration — just run docker-compose up --build and the table is created automatically.

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When you need Alembic

Alembic is needed when you make changes to existing tables — adding columns, renaming columns, changing types, adding indexes. create_all() does not modify tables that already exist.

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Setting up Alembic

Initialize Alembic from the project root: 
cd my-api
alembic init alembic
Edit alembic.ini to set your database URL: 
sqlalchemy.url = postgresql://postgres:test@localhost/postgres
Edit alembic/env.py to point at BackAnt’s Base: 
from startup.Alchemy import Base
target_metadata = Base.metadata
Also ensure all models are imported before Base.metadata is referenced: 
import models.Users_model
import models.Orders_model
# ... all your models

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Generating a migration

After changing a model (e.g. adding a phone column to Users), generate a migration: 
alembic revision --autogenerate -m "add phone to users"
Alembic compares your SQLAlchemy models against the current database schema and generates an upgrade() / downgrade() script in alembic/versions/.

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Applying migrations

alembic upgrade head

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Rolling back

alembic downgrade -1   # one step back
alembic downgrade base  # all the way back

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CLEAR_DB in development

For rapid iteration during development, CLEAR_DB=True in your .env drops all tables and recreates them from scratch on every restart. This is faster than running Alembic but destroys all data: 
CLEAR_DB=True
Never use CLEAR_DB=True in production. Always use Alembic migrations for production schema changes.

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Migration checklist

  1. Modify the SQLAlchemy model in api/models/
  2. Run alembic revision --autogenerate -m "description"
  3. Review the generated migration in alembic/versions/
  4. Run alembic upgrade head
  5. Rebuild your Docker image for deployment