JPA/Hibernate Optmistic locking works by using some field to store the last modified version (e.g. timestamp, long) and then comparing the version of the entity in the session with the entity in the database to see if the change can be saved. For this to work you need to have a field in your entity … Read more
Optimistic locking is the way to go, but as you might have noticed already, your code will never raise ActiveRecord::StaleObjectError, since child object creation in has_many association skips the locking mechanism. Take a look at the following SQL: UPDATE `scheduled_runs` SET `lock_version` = COALESCE(`lock_version`, 0) + 1, `attendances_count` = COALESCE(`attendances_count`, 0) + 1 WHERE (`id` … Read more
To partially update an entity, you should use @SessionAttributes to store the model in session between requests. You could use hidden form fields, but session is more secure. To use P/R/G with validation, use flashAttributes To secure fields use webDataBinder.setAllowedFields(“field1″,”field2”,…) or create a class specific to the form then copy values to your entity. Entities … Read more
Optimistic Locking is a strategy where you read a record, take note of a version number (other methods to do this involve dates, timestamps or checksums/hashes) and check that the version hasn’t changed before you write the record back. When you write the record back you filter the update on the version to make sure … Read more