问题
In Doctrine/Symfony3, how would I best check whether a record is about to be changed in order to delete/create a new one instead of updating?
Context: I'm loading a large price list csv into the database every time the supplier sends one. It is important that updated prices are not reflected in previously placed orders. Of course I could soft-delete all objects every time the list is uploaded, and create new ones, but that would make the database unnecessarily large and require unneccessary calls.
Therefore I want to soft-delete an object and create a new one only when it has been changed.
回答1:
I understand your requested workflow as:
- if entity has changed
- soft delete it
- create new record with new values
You need 2 steps to do that
1) use https://github.com/simplethings/EntityAudit to create new object on change
2) add EventSubscriber that listens to prePersist (or preFlush/preUpdate; pick the one that suits you best), and use similar process as in package above (seek for xxxSubscriber/xxxListener) to soft delete it.
来源：https://stackoverflow.com/questions/38423582/doctrine-on-persist-soft-delete-only-if-object-has-changed