many-to-many

I've three tables User, Device and Role. I have created a many-to-many relation b/w User and Device like this; #Many-to-Many relation between User and Devices userDevices = db.Table("user_devices", db.Column("id", db.Integer, primary_key=True), db.Column("user_id", db.Integer, db.ForeignKey("user.id")), db.Column("device_id", db.Integer, db.ForeignKey("device.id")))) class User(db.Model): __tablename__ = 'user' id = db.Column(db.Integer, primary_key=True) username = db.Column(db.String(60), index=True, unique=True) devices = db.relationship("Device", secondary=userDevices, backref=db.backref(

There are 3 tables: shelf, section and shelf_has_section intermediate table to support n-m relation. The schema build from symfony doctrine:build-schema looks as following. Simply, shelf(id, position) section(id, name) shelf_has_section(shelf_id, section_id, number_of_books) The schema. Shelf: connection: doctrine tableName: shelf columns: id: type: integer(4) fixed: false unsigned: true primary: true autoincrement: true position: type: string(255) primary: false notnull: true autoincrement: false relations: ShelfHasSection: local: id foreign: shelf_id type: many Section: connection: doctrine

There's a many-to-many UserFeed table that stands between User and Feed and denotes a twitter-like follow relationship. It only has two fields, which form a composite key: UserID and FeedID . I need to write a method that will subscribe or unsubscribe a user from a feed based on a boolean flag. public void SetSubscriptionFlag (int userId, int storeId, bool subscribe) { } I'm new to Entity Framework so I'm trying to find and follow an "EF-ish" way to accomplish this. My initial thoughts are: Instead of working with the middle UserFeed class, I should create a many-to-many Subscriptions property

I'm stuck with this problem for so long that I think that I'm missing something obvious. Here's simplified model of my case: There is Patient that has all meds that he/she takes. And there is Medicine that has all patients who takes it. // Patient model Yo.Patient = DS.Model.extend({ firstName: DS.attr('string'), lastName: DS.attr('string'), meds: DS.hasMany('medicine') }); // Medicine model Yo.Medicine = DS.Model.extend({ title: DS.attr('string'), patients: DS.hasMany('patient') }); I've read official manual and many resources. The last one and closest to my case was this Toptal tutorial .

I have some trouble with Hibernate during a ManyToMany association :/ I want to have a user with his contacts. The association Table is used to have a creation_date of the association and her status (ex. Active, inactive, etc...) Hibernate version : 5.2.17 Spring boot : 2.0.5 My class USER : @Entity(name = "user") public class User implements Serializable { @ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY) @JoinTable(name = "assoc_user_user", joinColumns = {@JoinColumn(name = "id.myself.id")}, inverseJoinColumns = {@JoinColumn(name = "id.contact.id")}) private List<AssocUserUser>