I have different entities like:
Element, Status, Action, Contributor ...
And I need to create an entity, let say Synonym, which can be related to one of these previous entities
My entity Synonym, can be a synonym of the entity Element or Status or Action ...
I try to use a MappedSuperclass but I'm really lost.
I think this kind of relation is common and must be easy to create with doctrine but I can't find the good way.
Related
Assume we have an entity "ticket". That entity can be related 1:1 to an entity "customer" OR to an entity "company", but never to both, but the ticket can also have no relation to one of these both entities at all.
How is this possible in doctrine/symfony?
I dont know your model but at database level the foreign keys in the ticket entity(customer_id and company_id) should be nullables in order to let one of them or both empty. At doctrine/entity level the only way is to use a validator option to check your requirements.
I guess wich better suits you is the callback validator but is your to decide
Let's say I have a Setting entity with some fields like IntValue, dateValue, stringValue and some linked entities, like countries (ManyToMany to entity Country), languages (ManyToMany to Language) etc.
Settings are created by users and assigned to specific objects (not important here, but I wanted to clarify).
Now I suddenly need to have UserDefaultSetting, which will be the same, but with additional user field (ManyToOne to User entity).
I tried to extend existing Setting entity class with one more field added. The problem is, as I looked at the schema update SQL, it created new table for the new entity, but without all the tables needed to ORM connections (mostly ManyToMany). Just one table with "scalar" fields.
So previously I've had setting table with int_value, date_value etc. but also setting_country and setting_language tables, linking ManyToMany relations. After creating child entity, Doctrine created only user_default_setting table with int_value, date_value etc. and additionally user_id column, but I can't see any relation/link tables.
I know I should've been do it with abstract base entity class, but at the time I started, I didn't know that and now part of the project is on production (don't look at me like that, I blame the client) and I don't want to change that "base" class now. Can I inherit everything from non-abstract entity class in a way it will work?
UPDATE: everything explained. See Cerad's comment. Thanks!
I have entities "Article" and "Product". Now I want to add comments to these 2 entities. Should I create 2 different entities "ArticleComment" and "ProductComment" with the same properties, and build a ManyToOne relation to their respective entity, or create a single "Comment" entity and find a way to build a relation to both "Article" and "Product" entities. Considering solution #2, how could I do that ?
Considering solution #2, how could I do that ?
One way would be to use Single Table Inheritance
Single Table Inheritance is an inheritance mapping strategy where all classes of a hierarchy are mapped to a single database table. In order to distinguish which row represents which type in the hierarchy a so-called discriminator column is used.
This means that you can easily create two separate entities ArticleComment and ProductComment both extending Comment. Then you use the advantages DiscriminatorMap column provides.
Your Comment entity could hold a relation called parent for instance that would refer to either your Article or Product entities. By creating new instance of ArticleComment or ProductComment your discriminator map field would be automatically populated depending on which type you're using.
This would also give you advantages with using DQL to query related comments by their type. Example from documentation:
$query = $em->createQuery('SELECT u FROM Doctrine\Tests\Models\Company\CompanyPerson u WHERE u INSTANCE OF Doctrine\Tests\Models\Company\CompanyEmployee');
And more. You can read that chapter here. Of course this is just a sample and you can use completely different approach.
I have 2 entities, User and Profile. Profile has in-symfony relation with User, but there is no in-database relation (no foreign key, no cascade) - only simple int column named user_id and nothing more.
Problem is obvious: when i delete user - associated profiles persists, but their user_id points to non-existing user row.
Since I use in-symfony relations when i fetch profile from database it fetches also related user entity. I expected that if there is no row with specific ID, it would just leave null or at least throw an exception or something.
Problem is that symfony creates empty User entity object with only id set. rest of its fields are null.
I know solution would be to create FK, constraints etc ... but I'm not allowed to touch anything in database schema.
How can I manage this problem ? I could even leave those empty object if only i had simple way to determine if they exist in database inside TWIG - so i would know if i can display {{ profile.user.email }} for example.
Fast and dirty solution, as you ask, is to use this test: http://twig.sensiolabs.org/doc/tests/defined.html
But I strongly recommend to rework your entity relations.
Found solution: its fetch: EAGER set to problematic mapping in doctrine.
By default doctrine uses LAZY fetching what results in using Proxy classes generated by doctrine for related entity. That class is almost same as real entity class. Difference is inside getter methods that before returning value performs fetching entity from database.
At this point, when you call getter on such proxy, doctrine tries to find entity in database using its ID, and since it doesn't find anything it throws exception.
When using EAGER fetching doctrine performs fetching of related entities on the same time when it fetches main entity and if it doesn't find it then sets null on relation field.
Using Docrine2 entities, I have a "list" entity, with a manytomany relationship with "item".
I need to manipulate and save the order of the items in the list. I can't figure out how to accomplish this using Doctrine2. What I want is a joiner table that looks something like:
list_item
=========
list_id
item_id
sort_order
All I can find is this outdated to-do item: http://www.doctrine-project.org/jira/browse/DDC-213
Can I accomplish this using Doctrine? Or is there some other way I should be going about this?
Thanks.
Here is an exerpt from this docs section, that answers your question:
Real many-to-many associations are less common. [...] Why are many-to-many associations less common? Because frequently you want to associate additional attributes with an association, in which case you introduce an association class. Consequently, the direct many-to-many association disappears and is replaced by one-to-many/many-to-one associations between the 3 participating classes.