Alembic Migration Best Practices

Naming Conventions — Define Once

# BAD: no naming convention — anonymous constraints break downgrades
class Base(DeclarativeBase):
    pass

# GOOD: explicit naming convention
convention = {
    "ix": "ix_%(table_name)s_%(column_0_label)s",
    "uq": "uq_%(table_name)s_%(column_0_name)s",
    "ck": "ck_%(table_name)s_%(constraint_name)s",
    "fk": "fk_%(table_name)s_%(column_0_name)s_%(referred_table_name)s",
    "pk": "pk_%(table_name)s",
}