From c33e03d7b1c362ebe50200371df4dabc21073a08 Mon Sep 17 00:00:00 2001 From: Peter Cock Date: Tue, 5 Nov 2024 19:08:02 +0000 Subject: [PATCH] Clarify what autogenerate compares I was struggling with empty upgrade/downgrade functions because both my database and my ORM were up to date. I wrongly assumed the comparison was against the previous database scheme as per the prior revision script(s). --- docs/build/autogenerate.rst | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/docs/build/autogenerate.rst b/docs/build/autogenerate.rst index 519aa5bc..835d4073 100644 --- a/docs/build/autogenerate.rst +++ b/docs/build/autogenerate.rst @@ -1,10 +1,12 @@ Auto Generating Migrations =========================== -Alembic can view the status of the database and compare against the table metadata -in the application, generating the "obvious" migrations based on a comparison. This -is achieved using the ``--autogenerate`` option to the ``alembic revision`` command, -which places so-called *candidate* migrations into our new migrations file. We +Alembic can view the status of the database (pointed to by ``sqlalchemy.url`` in +your ``alemic.ini`` file using the *previous* schema) and compare against the +table metadata in the application (your ORM which defines the *latest* schema), +generating the "obvious" migrations based on a comparison. This is achieved +using the ``--autogenerate`` option to the ``alembic revision`` command, which +places so-called *candidate* migrations into our new migrations file. We review and modify these by hand as needed, then proceed normally. To use autogenerate, we first need to modify our ``env.py`` so that it gets access -- 2.47.3