many-to-many

问题 I'm a beginner on Synfony2 and doctrine usage. I've created two entities as following : For EndUser Entity (extension of FOSUserBundle ): /** * EndUser * * @ORM\Table() * @ORM\Entity(repositoryClass="Core\CustomerBundle\Entity\EndUserRepository") */ class EndUser extends BaseUser { /** * @var integer * * @ORM\Column(name="id", type="integer") * @ORM\Id * @ORM\GeneratedValue(strategy="AUTO") */ protected $id; /** * @ORM\ManyToMany(targetEntity="Core\GeneralBundle\Entity\Discipline", mappedBy=

问题 Can someone help me figure out what code I should put in my change_default method? I would like to be able to do something like this... user = User.find(1) user.companies.first.default! or user.companies.find_by_company_id(2).default! My code: class Role < ActiveRecord::Base before_save :change_default belongs_to :user belongs_to :company def change_default #update default field for to false for current scope #Update current record default field to true #this is what I currently have, but it

问题 I am working on an application where my database objects often have multiple parents and multiple children, and would like to create a SQLAlchemy query that will return all descendants of an object. Realizing that I am basically trying to store a graph in a SQL database, I found that setting up a self-referential many-to-many schema got me most of the way there, but I am having trouble writing the query to return all descendants of a node. I tried to follow SQLA's recursive CTE example, which

问题 I have the following relationships (Business rules): User_Company : Many-to-many (multiple companies per user, multiple users per company) Ownership : One-to-One (For each entry in relationship table, it specifies whether user is an owner or employee. If owner then a percentage must be there) Company_ownership : One-to-many for company (Recursive relationship), as another company can also be an owner in a company, percentage must be given. So ownership or a company can be made up of a number

问题 I've got app with model where prescriptions are connected with medicines via relations table. I use one form to create one prescription with 5 relations which contains information about medicine_id, amount, daily and so on. However, medicine table has got a lot more information and thats what I would like to use when validating. For example - I want to check if field dose from table medicines is like `'%pills'. If so, I would like to do some calculation to check if an amount that user put

问题 I have two models lets suppose class A < ActiveRecord::Base has_many :bs end class B < ActiveRecord::Base belogns_to :a end now because of some system changes I need to convert this association to many to many some thing like this class A < ActiveRecord::Base has_and_belongs_to_many :bs end class B < ActiveRecord::Base has_and_belongs_to_many :as end OR class A < ActiveRecord::Base has_many :cs has_many :bs, through: :cs end class B < ActiveRecord::Base has_many :cs has_many :as, through: :cs

问题 I have created this model: Vendor_Key table contains the unique Vendor Numbers of table 1,2 and 3. The only table that has unique values is the Vendor_Key table. However, I can't get the relationships to work: PowerPivot can't identify the relationship either. Nonetheless, the relationships between Vendor_Key and Table_4 works correctly, but it doesn't when I add a field from another table. I have found these articles related to the subject, but I think this issue may more complex since I am

问题 I am building a Laravel application with a users table and an activities table, and a many-to-many relationship between activities and users implemented with a pivot table called assignments: users: id, ... activities: id, ... assignments: id, activity_id, user_id, ... I need to keep a record of each time a user completes an activity. A user can complete the same activity many times. I am trying to decide on the best way to model this in the database. The options as far as I can see are: a

问题 Here is where I am at right now. I have four tables: task, project, opportunity, and task_xref. The project and opportunity tables each have a one-to-many relationship with task. I am storing those relationships in task_xref. The schema looks something like this for each table (simplified): task ---- id(pk) name project ------- id(pk) name ... opportunity ----------- id(pk) name ... task_xref --------- task_id(task id) fkey(other table id) Assume that the keys in project and opportunity will

问题 I have many to many relationship between Books <--> Account How can i write DQL with condition on associative table? for example SQL: SELECT books.*, account.id FROM books LEFT JOIN account_books ON books.id = account_books.books_id AND account_books.account_id = 17 LEFT JOIN account ON account.id = account_books.account_id 回答1: In your BooksRepository, should be something like that public function getAccountBooks($accountId) { return $this->getEntityManager() ->createQueryBuilder() ->select(