For a project I need to have a relation between an entity "User" <-> "Form" <-> list of "FormField". The FormField class is mother of "TextFormField", "SelectFormField"...
I used class Table Inheritance but when I do $user->getForm() there are one left join by form field child. How can I avoid that to improve performances? Single table inheritance is not possible.
Does anyone have any idea about that ?
You can take a look at Sulu Form Bundle. Even though is not stable yet, it is really well developed. You should take a look on how they model their classes here, and their doctrine mappings here. That should give you an idea.
Related
I manage complex entities, with multiple and different relationships with other entities, which themselves are linked to multiple other entities sometime.
I am making an edit form, and would like to avoid having to code manually different Doctrine 2 queries to udpate every entity linked to the modified entity.
Is it possible to cascade merge entities in Doctrine 2 ? By that, I mean modifying an entity and its linked entities (oneToMany, ManyToMany... relationships) and then applying the changes to the entity and the linked entities in cascade.
If not, what is the 'clean' way to apply modifications to all the concerned entities ? Does it need to be manually done, by calling merge or update on every entity ?
It seems you are working on Symfony (correct me if I'm wrong).
On symfony forms, when you are working with underlying objects, you sometimes need to put 'by_reference' option to 'false' in order to correctly handle the underlying modified objects.
See that : https://symfony.com/doc/current/reference/forms/types/form.html#by-reference
Hope it helps.
Most probably the problem has nothing to do with symfony but more with your doctrine relationships. You should check your associations as changes made only to the inverse side of an association are ignored by doctrine. Refer to the documentation.
I am building an application where a User can have relation with multiple kind of entities : skills, tools, styles.
Those relations contain extra info like a rating.
My user entity will have three different attributes (skills, tools, styles) but I would like to use the same intermediary table for each of those relations.
I plan to build something like that :
User
Name
...
Tools
Skills
Style
UserRates
User id
Tool/style/skill id
Relation type ("tool", "style", "skill")
Rate
Tools
Name
...
Skills
Name
...
Styles
Name
...
Another similar scenario would be to build a system to rate anything (blog posts, events, images, ...).
I can't imagine a system where you have to rebuild the relation for each new notable entity.
My questions are:
Is this kind of relation is doable in SF2?
Do you know any good example / article?
How would you do it ? I guess I need a custom repository and custom setters/getters ?
Tools
Entities are handled by an ORM. I'm guessing you're using Doctrine as it comes standard with Symfony2+.
How to do relationships
Relations are done with Doctrine mappings which you can find here on their documentation website.
Note: the annotations in the doctrine documentation do not have the #ORM/ prefix, which Entities which are part of Symfony2 require (look at "use" statments to see why). So you'll have to add them yourself.
PS: Unless you have very good reason to relate all those entities via one intermediary table, don't do it.
I should also note that when dealing with an ORM you should not be thinking about tables, but about objects. Doctrine will generate an intermidiary table for ManyToMany relationsips automatically.
You'll only need to create one yourself (and thus have ManyToOne IntermidiaryEntity OneToMany relationships) when the relation has to carry extra information.
As someone has already suggested, I suggest reading the relevant chapter in Symfony2's amazing book.
I'm actually having 3 entities: Bounty, Document, and Comment. When i first made the Comment entity, it was to serve the document Commentary purpose. Later i have added a newer entity called "Bounty", and i was expecting to use the same Comment entity that i was already using in the Document entity.
I wish to avoid having one DocumentComment entity, and another BountyComment entity.
Is having one Comment Entity is a good way to procede, or should i rather separate them in two different entities ?
If grouping entites is a good practice, how can i make them fit when there can be duplicate entry ?
If both identities have the exact same structure and this fact is never going to change, you could group them together. However, every comment belongs to some other entity, so if it belongs to a Document, it needs a property "document". If it belongs to a Bounty, it needs a property "bounty". So the two are not the same.
If you are using ORM (e.g Doctrine), you can use a shared base class and extend from it. Doctrine will create seperate tables for each type, but you can share functionality between the entity classes. See http://doctrine-orm.readthedocs.org/en/latest/reference/inheritance-mapping.html
Would it be possible to create a similar entity based on another one? For example, what if I'd like to have user specific tables that are based on one entity. Without any ORM I would just create the same table with a different prefix and do the queries on the table with the specific prefix.
Not sure how to tackle the problem with Symfony 2.5 and Doctrine and I just can't find a concrete example anywhere around, but seems like the solution might be around the Doctrine Event Manager and the Load ClassMetadata event. I just can't make sense out of the documentation.
Without exactly knowing how your schema looks or what you're trying to achieve, it's hard to give a precise answer. But let's try:
If you have two entities which share a common set of properties, but differ in others, you basically do the typical OOP inheritance thing, you create an abstract parent class with the common stuff, and two children with their specific properties.
In Doctrine, there are different inheritance strageties. Read about them at http://doctrine-orm.readthedocs.org/en/latest/reference/inheritance-mapping.html
Each of them has their pros and cons. Basically, you can select if you want everything to be in one or in two tables. Set up a test case and check what works better for you.
Note: The class properties in an abstract superclass (no matter which strategy) must always be private.
I really like where symfony 2 is headed, I just really dont like doctrine, I love codeigniters active record db system, is there anyway I can completely remove doctrine from symfony and replace it with a DAL like of codeigniters ?
Doctrine 2 is a pure Data Mapper pattern implementation. Its advantage over Active Record is that you don't have to bend your model to a database schema or vice versa. In most cases your model and schema may evolve separately; you'll need to update the mapping metadata only.
Plus you don't have to extend/implement any special classes/interfaces. Your model consists of POPOs (Plain Old PHP Objects) and the mapping is managed by an external object — an entity manager. This allows for good OO design on the PHP side and good schema design on the database side.
So, I suggest you rethink your desire to go back to Active Record. It may take some time for the paradigm shift but it's worth it.
The thing that Doctrine is a default choice doesn't mean it's the only one. It's not tightly coupled to Symfony and can be replaced.
Symfony provides sensible defaults but gives you the freedom to change them.
For example, you might use Propel. It implements Active Record (as opposed to Doctrine2).
You can write your own ORM implementation if you'd like to.
Note that apart from ORM, Doctrine has some useful helper libraries. For example annotation reader is used in Symfony to parse annotations. If you use them you'll need this part of Doctrine.