I have 2 Doctrine Entities with many-to-many relations. When I edit the first entity I want to be able to select the checkboxes that have the data from the 2nd entity to establish the joins for particular entry.
It works fine on creating a new Entry (using Array Collection), but when I want to edit an Entry - it adds the ones that I have selected without removing the previous choice (unchecking).
Which way would be the correct way to do that and how?
Remove all the Join table data for the Entry that is being updated,
then set the new data. (How can I remove it from the join table that
is not an Entity?)
Pass all the data from the 2nd Entity and remove
those that aren't checked (seems super-clumsy?)
Some other way I am not aware of?
I am not using Symfony, just Doctrine.
Doctrine makes working with the many-to-many associations quite easy. Your associations are stored into an ArrayCollection class that has some methods that can help you. First of all, check all the available methods for the ArrayCollection here (Doctrine API - ArrayCollection)
In your case, I'd use this approach: use the clear method on your ArrayCollection that contains the relationship with the 2nd entity and populate it again with the checked elements. After this, call the flush method on the entitymanager.
Another approach consists in filtering your collection (with the filter method) for getting a brand new ArrayCollection that contains only the elements that are checked. Like the first approach, associate this new collection to the relationship's ArrayCollection and call the flush method on the entitymanager.
Related
I have a Entity in my database (say Member) which has many relationships with other tables (6 relationships to be exact). Some of them I don't want mapped with the ORM (I mean linked to this Entity) because they may have many records (like MemberAccessLogs for example) and some other load many other entities.
Now I want this Member Entity to have an isDeletable method so I can disable exclude button in administration page.
If I where to do this the traditional way, I would have to declare the associations with all the other tables in the entity class, including MemberAccessLogs and I would put the method in it so I could test if these associations are empty.
But AFAIU, I would have to make a fetch (or at least a count) to the association's tables in order check for empty.
Another way would be to fetch the Members I want shown and then make a separate query to check for empty with a low cost exists(select * from table limit 1) in these sub-tables and then populate the isDeletable method in Member programmatically before pass it to Twig.
But I found this solution cumbersome. Anyone has a better way to do this ?
Just for the record: Some people may think this is "premature optimization". I maintain (contrary to some), that you should think ahead when you are programming and don't this this is bad. But I really think this isn't the place to discuss it. Please let's focus on the question asked ok ? :)
Edit
To easily prove that limit 1 is increadibly faster than count, I did a small test in a table in my database that has more than 20 million lines. Here are the results:
select count(*) from loga [20 million+ table]
20678473
1 row(s) fetched - 27023ms
select exists(select null from loga limit 1)
true
1 row(s) fetched - 2ms
I guess 13511,5 times faster is conclusive enough. :D
Extra lazy
You could look into extra-lazy associations.
Basically you map all associations as you normally would, and add fetch="EXTRA_LAZY":
/**
* #Entity
*/
class CmsGroup
{
/**
* #ManyToMany(targetEntity="CmsUser", mappedBy="groups", fetch="EXTRA_LAZY")
*/
public $users;
}
Now Doctrine will not load the complete collection into memory the first time it's accessed, but performs specialized queries to load the parts you actually need at that moment.
So $users->count() (or count($users)) on the collection would trigger a simple count-query in stead of loading the complete collection into memory.
PostLoad
You could use an postLoad event to determine if such an entity is deletable. This postLoad event is called after an entity is constructed by the EntityManager, so when the entity is loaded.
Add an unmapped property ($isDeletable) to the entity that stores whether the entity can be deleted or not.
Create an entity listener that listens to the postLoad event. The listener can have the EntityManager, DBAL Connection, or anything else injected. With that dependency you could perform whatever query you want and use the result to set $isDeletable.
The result is a single additional query when the entity is loaded, after which the entity "knows" whether it's deletable or not.
An example of using the postLoad event can found in a Cookbook entry on the Strategy Pattern
Do note that when the conditions that determine whether it's deletable or not change, the value of $isDeletable could become incorrect. To resolve this issue, you could keep track of those conditions:
Keep track
Add a mapped property ($isDeletable) to the entity that stores whether the entity can be deleted or not. It would probably start with true.
When something is added to an association which would mean that the entity is no longer deletable, set $isDeletable to false.
When something is removed from an association that which would mean that the entity is deletable again, set $isDeletable to true.
In other words: with every change you keep track of whether the entity is deletable or not.
This way you won't need any additional queries at all.
There's a Cookbook entry on aggregate fields that explains this concept very well.
I have mulutiselect option enabled in select html code, my frontend look like this:
For example if user unselect some option and select other how can I update it in database, any idea?
If you have ManyToMany relationships between say Group and Project you can use sync() method to maintain association as below,
$group->projects()->sync([$projId1, $projId2]);
Above will remove all previous association between current group($group) and projects and associates newly supplied projects i.e. $projId1, $projId2.
If you want to maintain previous associations pass false as a second argument in sync() as below,
$group->projects()->sync([$projId1, $projId2], false);
Above code will maintain previous Group and Project association and will also associate passed projects.
I'm trying to figure out the correct way to map my three entities together. I have a "HouseType", a "Resource" and a HouseType can have multiple Resources (with an integer indicating how many of that resource they have). So I have three tables, the house_type, resource and house_type_resource (with house_type_id, resource_id, and num).
I can't figure out what type of association mapping I should do. I'm reading this page: http://docs.doctrine-project.org/en/latest/reference/association-mapping.html but I don't see one that's like mine, where I have a third entity to represent the join table, because it has a specific property that needs to be included (the num). It's sort of like the "Many-To-Many, Unidirectional" but I need that third Entity mapped in there. I see the note at the end about doing an Association class but I don't see any more info on that.
Once you start adding extra columns, Doctrine stops treating it as a pure many-to-many relationship because there is extra data, and this data should be managed with an entity. You should create a new entity called HouseTypeResource, then create one-to-many relationships with this inside your HouseType and Resource entities.
I have two tables with a ManyToMany relationship. I needed to add some extra fields to this relationship, so I created a new entity that has a ManyToOne relationship with each of the two tables. The issue I'm having is with removing the relationship entity. I don't want to remove entries in either of the two tables, I just want to remove the relationship. What I've done to set up the relating entity is pretty much described here:
Doctrine2: Best way to handle many-to-many with extra columns in reference table
To remove the relationship, I've tried removing the relating element from each of the two other table entries, and then setting the reference to those tables to null in the relating entity. That doesn't seem to work; Doctrine tries to execute a query to update the entry in the relating table and set both the foreign keys to null. I would expect it to remove the entry in the relating table, if all references to it have been removed.
Let me know if you'd like to see my entities, or if this makes enough sense as it stands.
Actually, deleting the entity that acts as "join-table" does the trick.
Nothing should be cascaded.
So assuming you have a relation like
User <- UserGroup -> Group
You just need to remove the UserGroup entity.
If you remove User or Group, and you have set cascade persist operations correctly, also UserGroup will go. You can also use orphanRemoval to avoid having UserGroup assigned to different User or Group elements.
Is there a way to have something like this in doctrine:
class Entity {
/**
* #Column(name="related_entity_id")
*/
private $relatedEntityId;
/**
* #ManyToOne(targetEntity="RelatedEntitiy")
* #JoinColumn(name="related_entity_id", referencedColumnName="id")
*/
private $relatedEntity;
}
What I want to do I do something like this:
call Entity::setRelatedEntityId($someId), and persist the entity,
and have the entity return the related entity by calling Entity::getRelatedEntity().
The related entity is selected from a table which will be strictly limited and it will never dynamically grow at runtime, so there is a finite number of related entity ids.
At the time of creating a new Entity, I'd like to set the related entity id, but without having to fetch the whole related entity from the database.
As far as I could test this, it does not work, because if I set the relatedEntityId but not the relatedEntity, Doctrine automatically sets the related_entity_id column to null, since basically no relationship has been established.
I've tried to do something like this also:
remove the relatedEntityId property, and use
Entity::setRelatedEntity(new RelatedEntity($relEntId))
the constructor of the RelatedEntity will set the id, but not other values.
I do not want to persist the RelatedEntity (it's values are already set in the DB for the given $relEntId), but this time Doctrine signals an error at flush, because it has an unpersisted entity.
Basically, what I want to do is create a relationship without knowing anyhing but the Id of the related entity. If there is some other way this can be done, please share.
Thanks in advance
EDIT:
I've found a workaround. Since the RelatedEntities will be a limited set of immutable objects, I've done the following:
use the entityManager to find all RelatedEntities;
inject the list to the object that will be creating new Entities
when creating a new Entity, select one of the RelatedEntities from the list as its RelatedEntity
I'll leave the question open for a day or two, just in case somebody comes up with something better.
Use the entity proxy:
Entity::setRelatedEntity($entityManager->getReference('RelatedEntity', $relEntId))
I don't think this is supposed to work like how you described :)
The entity you add must be a Doctrine managed object, so that means you have to load it yourself first using the find() family of methods.
Based on my experience with Doctrine 2 further elaborated here http://ssmusoke.wordpress.com/2012/03/25/doctrine2-day-3-proxies-associations-relationships/
My approach is as follows:
a) Have only the $relatedEntity property
b) Add a getRelatedEntityId() function which returns the id value from $relatedEntity
c) Add a setRelatedEntityId() which sets the $relatedEntity object - you may need to load it from the database, saves you from polluting other layers when u only have the id of the related entity
d) Add getRelatedEntity() and setRelatedEntity() functions
BOTTOM LINE: You cannot have a property for the foreign key column and the mapped property as Doctrine gets confused