fix: Correctly Generate DDL for ALTER COLUMN ... SET DEFAULT #726
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Alembic expects `get_column_default_string` to be implemented in order to use it for `ALTER TABLE.. ALTER COLUMN .. SET DEFAULT` DDL. In our case, this means wrapping the default value in parentheses. We implement `get_column_default_string` and have it add parentheses for use in both `CREATE TABLE` and `ALTER TABLE` DDL. Call path for alembic relying on `get_column_default_string` is here: https://github.com/sqlalchemy/alembic/blob/cd4f404358f101b2b930013c609c074baca61468/alembic/ddl/base.py#L252 https://github.com/sqlalchemy/alembic/blob/cd4f404358f101b2b930013c609c074baca61468/alembic/ddl/base.py#L315
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Aug 18, 2025
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Closing this, as all the changes in this PR were covered in #733 |
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Alembic expects
get_column_default_stringto be implemented in order to use it forALTER TABLE.. ALTER COLUMN .. SET DEFAULTDDL. In our case, this means wrapping the default value in parentheses. We implementget_column_default_stringand have it add parentheses for use in bothCREATE TABLEandALTER TABLEDDL.Call path for alembic relying on
get_column_default_stringis here:https://github.com/sqlalchemy/alembic/blob/cd4f404358f101b2b930013c609c074baca61468/alembic/ddl/base.py#L252 https://github.com/sqlalchemy/alembic/blob/cd4f404358f101b2b930013c609c074baca61468/alembic/ddl/base.py#L315
Fixes: #727