How can we fix this database integrity problem?
Inconsistent database table and entity definitions: column 'OSUSR_jjg_Computer.IS_ACTIVE' exists in database, but there is no corresponding attribute in entity 'Computer'.
The behavior is very common when developing with the OutSystems Platform.
You are seeing that warning because you had that 'IS_ACTIVE' attribute in your 'Computer' entity, and then you deleted it via Development Environment.
This is a very common warning mainly in the development environment, because when developers are designing their applications, they usually delete or create new entity attribute, but the platform will never delete anything from the database. This is done intentionally to prevent data loss and also to allow for roll-back to previous versions of your applications.
This does not represent a problem, and you don't really need to remove the warning since it does not stop you from continue working normally.
Anyway, if you want to remove the warning, on On-Premise infrastructures you can access directly your database and delete the column, or, independently of your infrastructure, you can use the DBCleaner component available on our Forge.
And how to do it on DBCleaner?
You just need to select the Database Entities menu tab and then look on the Attributes section for the attribute you would like to delete. After that, you just need to click on the Drop button and the attribute will be deleted from the database and the warning will also disappear.