Hi Hung,
I agree with your fix. I've added an alter procedure in a new upgrade script for 2.3.8.2. It is in the repository now, but the setup page won't run this script until I change the version in mojoPortal.Business.DatabaseHelper.DBSchemaVersion
This means I can still edit the 2.3.8.2 upgrade script, once I increment the version and push it to the default branch then I can no longer edit the script because it will be executed.
So you can manually change it in your db for now and this script will run later but will just do the same change plus any other changes I may make in that script between now and then.
The setup system works a little different for mojoPortal core than for features. For features the setup page will run any scripts it finds that are newer than the current version of the feature, but for mojoPortal core it does an extra check against this method in DatabaseHelper and only runs scripts up to the version indicated there that are higher versions than ones previously run.
Best,
Joe