Flask-migrate: renaming columns - not dropping old and creating new

[asldevi]

How do I tell migrate that I want to rename the columns i.e, issue op.alter_column instead of op.drop(old_column) and op.add_column(new_column), so that the data is preserved?

[davidism]

From the Alembic docs:

Autogenerate can not detect:

• Changes of table name. These will come out as an add/drop of two different tables, and should be hand-edited into a name change instead.
• Changes of column name. Like table name changes, these are detected as a column add/drop pair, which is not at all the same as a name change.

You should review migrations before running them to ensure correctness, for this reason and others.

[miguelgrinberg]

As is mentioned in the document and in my tutorials, automatic migration generation is not 100% accurate. The migration scripts are meant to be hand-edited, consider the generated script a starting version. You should _always_ review and correct the generated scripts. Column renames is one example where there is really no safe way for the software to determine that you renamed a column.

[svenstaro]

Can't this be closed?

[miguelgrinberg]

Yes, I'm closing.