To generate migrations, you’ll need to be running MySQL locally.
brew install mysql
Reccomended SQL Client for local exploration: Sequel Pro
Start MySQL and connect
mysql.server start
mysql -u root
The password for root is blank by default. Just hit enter and you will enter the mysql console. See the MySQL docs for more info.
Run the following commands to create a user and a table for OK
create database ohdevel;
CREATE USER 'ohdev'@'localhost';
GRANT ALL PRIVILEGES ON ohdevel.* TO 'ohdev'@'localhost';
If the master branch is the current state of the production branch - start by checking out the master branch.
git checkout master
Make sure OK is using MySQL and not sqlite by setting the DATABASE_URL
environment variable. For Bash,
export DATABASE_URL=mysql://ohdev:@127.0.0.1:3306/ohdevel?charset=utf8mb4
# Rebuild the database
./manage.py resetdb
./manage.py db upgrade # Make sure this does not crash. If it does: see Common Errors below
Now you can checkout the branch with changes:
git checkout feature-branch
./manage.py db migrate -m "Added new feature"
That should produce the output along the lines of
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
INFO [alembic.autogenerate.compare] Detected added column 'assignment.published_scores'
Generating /dev/ok/server/migrations/versions/6ce2cf5c4534_publish_scores_for_assignments.py ... done
Check the file contents before running the migrations to make sure the changes make sense. There should not be unncessary changes. It’s ok to manually make changes to the script (or manually write a migration file) if needed.
Make sure the deploy the app. After it’s running, run
dokku maintenance:on officehours-web # maintenance message
dokku mysql:stop officehours-web # stop mysql so the migration can get a lock
dokku mysql:start officehours-web # start it back up
# optionally stamp it with the previous revision (if it doesn't have a history of migrations)
# dokku run officehours-web ./manage.py db stamp 5e2ef12760a4
dokku run officehours-web ./manage.py db upgrade
dokku maintenance:off officehours-web
dokku deploy officehours-web # to restart
to upgrade.
If you are getting long tracebacks that end in somethng like this
raise errorclass(errno, errorvalue)
sqlalchemy.exc.ProgrammingError: (pymysql.err.ProgrammingError) (1146, "Table 'ok-dev.client' doesn't exist") [SQL: 'ALTER TABLE client ADD COLUMN created DATETIME NOT NULL DEFAULT now()']
or
raise util.CommandError("Target database is not up to date.")
alembic.util.exc.CommandError: Target database is not up to date.
It’s likely that Alembic is trying to rerun migrations (or has not run all of the migrations in the folder)
If you are sure that the DB is up to date - find the ID most recent migration run (the most recent commit in them migrations folder should reveal the file most recently created) and then run
./manage.py db stamp f7f27412d13f
This tells alembic that the DB is at revision f7f27412d13f. Now running ./manage.py db upgrade should result in this output
$ ./manage.py db upgrade
INFO [alembic.runtime.migration] Context impl MySQLImpl.
INFO [alembic.runtime.migration] Will assume non-transactional DDL.
$
If that doesn’t resolve it - make sure there are not unrun migrations in the branch.
If the upgrade is hanging - it might be unable to get a lock to the database.