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view docs/dev/dbmigrations.rst @ 7963:46681ae86693
db: introduce migration step after 93834966ae01 dropped non-nullable inherit_default_permissions
The database migration step was lazily and naively skipped ... but that turns
out to be a problem when new users are added.
In the database, the original column 'inherit_default_permissions' was
marked as non-nullable without default value. In the Kallithea code after
commit 93834966ae01, the column 'inherit_default_permissions' was no longer
known, and thus not given a value when new users are added. As a result, the
database complained:
IntegrityError: (psycopg2.errors.NotNullViolation) null value in column "inherit_default_permissions" violates not-null constraint
Fix that now by adding an appropriate db migration step to actually remove
the columns.
Use meta reflection to check if columns exist before running the upgrade
step. The upgrade step only has to be run if it is an old database - not if
it has been created after the schema changes were introduced.
For the downgrade step, make sure to set a default value for non-nullable
columns.
author | Mads Kiilerich <mads@kiilerich.com> |
---|---|
date | Sat, 23 Nov 2019 02:27:19 +0100 |
parents | 3158cf0dafb7 |
children |
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======================= Database schema changes ======================= Kallithea uses Alembic for :ref:`database migrations <upgrade_db>` (upgrades and downgrades). If you are developing a Kallithea feature that requires database schema changes, you should make a matching Alembic database migration script: 1. :ref:`Create a Kallithea configuration and database <setup>` for testing the migration script, or use existing ``development.ini`` setup. Ensure that this database is up to date with the latest database schema *before* the changes you're currently developing. (Do not create the database while your new schema changes are applied.) 2. Create a separate throwaway configuration for iterating on the actual database changes:: kallithea-cli config-create temp.ini Edit the file to change database settings. SQLite is typically fine, but make sure to change the path to e.g. ``temp.db``, to avoid clobbering any existing database file. 3. Make your code changes (including database schema changes in ``db.py``). 4. After every database schema change, recreate the throwaway database to test the changes:: rm temp.db kallithea-cli db-create -c temp.ini --repos=/var/repos --user=doe --email doe@example.com --password=123456 --no-public-access --force-yes kallithea-cli repo-scan -c temp.ini 5. Once satisfied with the schema changes, auto-generate a draft Alembic script using the development database that has *not* been upgraded. (The generated script will upgrade the database to match the code.) :: alembic -c development.ini revision -m "area: add cool feature" --autogenerate 6. Edit the script to clean it up and fix any problems. Note that for changes that simply add columns, it may be appropriate to not remove them in the downgrade script (and instead do nothing), to avoid the loss of data. Unknown columns will simply be ignored by Kallithea versions predating your changes. 7. Run ``alembic -c development.ini upgrade head`` to apply changes to the (non-throwaway) database, and test the upgrade script. Also test downgrades. The included ``development.ini`` has full SQL logging enabled. If you're using another configuration file, you may want to enable it by setting ``level = DEBUG`` in section ``[handler_console_sql]``. The Alembic migration script should be committed in the same revision as the database schema (``db.py``) changes. See the `Alembic documentation`__ for more information, in particular the tutorial and the section about auto-generating migration scripts. .. __: http://alembic.zzzcomputing.com/en/latest/ Troubleshooting --------------- * If ``alembic --autogenerate`` responds "Target database is not up to date", you need to either first use Alembic to upgrade the database to the most recent version (before your changes), or recreate the database from scratch (without your schema changes applied).