Doctrine2中所有对象的全局基础对象的优缺点

Question

What are the pros and cons of using a global base entity for all entities in my Doctrine2 model?

I am considering having all of my domain entities extend a single generic base entity, so that I can specify the target entity of an association to be the base entity class, thereby allowing that association to hold any entity in my domain.

My associations will still be as specific as possible: an Order entity will contain Product objects, not Base objects. But more 'meta'-like functionality like status log items, authorization specs, etc., can be specified very generically by defining LogItems and AuthorizationRules having an association to BaseEntity, instead of with specific items.

I am not seeing this approach anywhere, but there seems to be some use or power to having all classes extend off a base Object entity ('Java-style'). But perhaps I am needlessly overcomplicating things.

Is a base entity in Doctrine2 a good idea?

Answer 1

You have it all described here:

http://doctrine-orm.readthedocs.org/en/latest/reference/inheritance-mapping.html

You can do inheritance from the OOP point of view(php) and map it to database(you can have persons and employees that are persons as well(or people)) but you cant have the database understand the inheritance(it's done in the db abstraction layer(doctrine)).

So each class you might want to have in relation, has to be and entity, meaning that both a person and and employee have to be entities. If you do it as single table inheritance, you could relate and entity to "Person" and then it would include employees also.

http://doctrine-orm.readthedocs.org/en/latest/reference/inheritance-mapping.html#single-table-inheritance http://martinfowler.com/eaaCatalog/singleTableInheritance.html