Sqlite lack of ALTER support, Alembic migration failing because of this. Solutions?
You can set a variable (render_as_batch=True) in the env.py file created with the initial migation.
context.configure( connection=connection, target_metadata=target_metadata, render_as_batch=True)It requires alembic > 0.7.0
This enables generation of batch operation migrations, i.e. creates a new table with the constraint, copies the existing data over, and removes the old table. See http://alembic.zzzcomputing.com/en/latest/batch.html#batch-mode-with-autogenerate
If you still encounter issues, be advised - there is still nuance with sqlite, e.g. http://alembic.zzzcomputing.com/en/latest/batch.html#dropping-unnamed-or-named-foreign-key-constraints