Optimistic locking allows multiple users to access the same record for edits and avoids
potential conflicts. In case when a user attempts to save the record upon some staled data
(because another user has modified the data), a [[StaleObjectException]] exception will be thrown,
and the update or deletion is skipped.
Optimistic locking is only supported by
BaseActiveRecord::update and
BaseActiveRecord::delete.
To use Optimistic locking:
1. Create a column to store the version number of each row. The column type should be
BIGINT DEFAULT 0.
Override this method to return the name of this column.
2. Add a
required validation rule for the version column to ensure the version value is submitted.
3. In the Web form that collects the user input, add a hidden field that stores
the lock version of the recording being updated.
4. In the controller action that does the data updating, try to catch the [[StaleObjectException]]
and implement necessary business logic (e.g. merging the changes, prompting stated data)
to resolve the conflict.
