many-to-many

问题 This is a follow up question to my previous question on: Core data: Managing employee contracts in a many-to-many relationship? There is a diagram on that question, and as a quick reminder there is the following: company --< contracts >-- employees I have been able to manually save 1 entity inside each of the entities, and verified them all in NSLog. I've created a CompanyListPage which lists all companies. The idea is that when you click on a company you will be presented with a list of all

问题 I am using RestKit to map the following JSON to core data. I have a many-to-many relationship set up in core data. A hopper can have many users and a user can have many hoppers. I am getting this error message: (entity: Hopper; id: 0x767d240 hopperToUsers = <relationship fault: 0x8352960 'hopperToUsers' ; So none of my users are being updated. The json: { "hoppers": [{ "bearing": 0, "created_at": "2013-07-26T07:57:00Z", "distance": 0.0, "id": 4, "lat": "30.422032", "lng": "-86.617069", "name"

问题 I have an "Export to CSV" button that exports all car models. When I export all cars into CSV, the "features" (e.g. AM/FM Radio, Moon Roof, Leather Interior, Bluetooth, GPS etc..) column displays as the following: [<Feature: GPS>, <Feature: Leather>] How do I get rid of all that other stuff, and just have "GPS, Leather"? MODEL class Features(models.Model): name = models.CharField(max_length=20) def __unicode__(self): return self.name class Car(models.Model): model_name = models.CharField(max

问题 I get really confused with many-to-many database relationships, so can some one please clarify how I would achieve this? I need a table of "Tags" (as in tag words) and a table for "Entries", such at many "Entries" could correspond to many Tag words. Right now I have my models like this: # models.py class Tags(models.Model): tag = models.CharField(max_length=255) entry = models.ManyToManyField(Entry) class Entry(models.Model): entry = models.CharField(max_length=255) description = models

问题 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:

问题 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:

问题 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

问题 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

问题 I'm using Fluent NHibernate's AutoMap feature to map my entities. Most of my entities inherit from a base class Entity which has a property public IList<Tag> Tags . The tags are in a separate table in the database, so I use a many-to-many relation. But Fluent NHibernate creates mappings for a one-to-many relation. I'd like to write a convention to override these mappings to use HasManyToMany(...) if the class inherits from Entity . Is this possible and how? The convention could either rely on

问题 I'm using Fluent NHibernate's AutoMap feature to map my entities. Most of my entities inherit from a base class Entity which has a property public IList<Tag> Tags . The tags are in a separate table in the database, so I use a many-to-many relation. But Fluent NHibernate creates mappings for a one-to-many relation. I'd like to write a convention to override these mappings to use HasManyToMany(...) if the class inherits from Entity . Is this possible and how? The convention could either rely on