I'm trying to get the SQL script generated from an alembic revision, but when I run:
alembic upgrade head --sql
It outputs the SQL of all revisions, and because there's a breaking revision in the middle (I haven't figured out why yet), I can't get the script from that point on. Moreover, I only want the SQL script of the last revision.
Is there a parameter to get that?
After some time trying to figure it out, and reading the docs, you can obtain the SQL of a single or multiple specific revisions by specifying start:end in the command line:
alembic upgrade <previous>:<current> --sql
It will even output the update to the alembic_version table.
The same works with downgrade:
alembic downgrade <current>:<previous> --sql