Can Alembic Autogenerate column alterations?

Question

I was able to use alembic --autogenerate for when adding / removing columns.

However, when I wanted to modify for example a \"url\" column from 200 charact

Answer 1

I also faced this issue, and on alembic 1.0.8 the context.configure in def run_migrations_online() function on migrations/env.py file will be like this:

with connectable.connect() as connection:
    context.configure(
        connection=connection,
        target_metadata=target_metadata,
        process_revision_directives=process_revision_directives,
        **current_app.extensions['migrate'].configure_args,
    )

Just remove or comment theprocess_revision_directives=process_revision_directives and then add the compare_type=True on that.

Like this:

with connectable.connect() as connection:
    context.configure(
        connection=connection,
        target_metadata=target_metadata,
        # process_revision_directives=process_revision_directives,
        **current_app.extensions['migrate'].configure_args,
        compare_type=True
    )