From 8b8e2c4f27a23efda97f43a6994bfa7f039e53aa Mon Sep 17 00:00:00 2001 From: Mike Bayer Date: Thu, 10 Dec 2015 12:15:23 -0500 Subject: [PATCH] - existing_server_default is not used to drop the previous schema type constraint; existing_type is. I haven't checked to see if this changed at some point but that's what the source code right now says. --- alembic/operations/ops.py | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/alembic/operations/ops.py b/alembic/operations/ops.py index 29f749e5..839c2da2 100644 --- a/alembic/operations/ops.py +++ b/alembic/operations/ops.py @@ -1345,9 +1345,9 @@ class AlterColumnOp(AlterTableOp): and :class:`~sqlalchemy.types.Enum` may also add or drop constraints which accompany those types on backends that don't support them natively. - The ``existing_server_default`` argument is - used in this case as well to remove a previous - constraint. + The ``existing_type`` argument is + used in this case to identify and remove a previous + constraint that was bound to the type object. :param table_name: string name of the target table. :param column_name: string name of the target column, -- 2.47.2