many-to-many

问题 Storing additional information for a Many-to-Many relationship I have the following two entities in a many-to-many relationship with the following model - Disease public class Disease { public Disease() { this.Indications = new HashSet<App.Models.Indication.Indication>(); this.LaboratoryParameters = new HashSet<App.Models.LaboratoryParameter.LaboratoryParameter>(); this.Medicines = new HashSet<App.Models.Medicines.Medicine>(); } [Key] [DatabaseGeneratedAttribute(DatabaseGeneratedOption

问题 I'm currently trying to implement a ManyToMany Relationship with Data in the JoinTable. I'm following this approach with the Eclipselink JPA Framework. But I'm getting the following exception: org.eclipse.persistence.exceptions.EntityManagerSetupException.predeployFailed(EntityManagerSetupException.java:210) ... 23 more Caused by: Exception [EclipseLink-7298] (Eclipse Persistence Services - 2.1.1.v20100817-r8050): org.eclipse.persistence.exceptions.ValidationException Exception Description:

问题 Rephrase of original question: I have your typical M:M relationship, in my case think of the User / Role example: USER, ROLE, USER_ROLE I need a second USER_ROLE table matching up User s to Role s. I won't get into specifics as to why that is (unless you need me to), but I am looking for a way to accomplish this with JPA AND without changing up the User and Role Entities. *I need a second USER_ROLE table to audit actions the User performs and which Role he was at the time the action was

问题 I am creating a photo sharing app for the iPhone using Parse.com and so far everything has been pretty easy and I just finished writing the code for uploading photos to the Parse server. So far, I have been using the default "_User" class. Here are some of the key types of data that are being stored for each user: objectId, username, email, and an array object called "friends" that contains the usernames of other users in the database that the user has added to their friends list. Now, I need

问题 I'm working on a bash script that create a simple project "from zero to CRUD" with some tool and Symfony 3 bin/console doctrine:generate:* It works fine but in the M:N association case i can't update data from the inverse side. I read some answers here and i started some tests but i'm confused among "cascade={"all"}" option, 'by_reference' => false and other suggests. What is the simplest way to do that starting from this basic example taken from the offical doctrine docs? /** @Entity */

问题 just see this picture : how to I select dorm_id(70)? dorm_id is home ides , and facility is the propertray of theme , each home has some facility for example home id 70 has these facilities (12,13,14,17,18) , how to I select number 70 from dorm_id column . its a search query that find dorm_id that has all facility thanks in advance 回答1: You can do it this way if you have your facility_id in a table called table_facility: select dorm_id from table_dorm group by dorm_id having count(distinct

问题 My question may look like the following question: yii2 - model load function does not set some model attributes However, the case here is different due to dealing with Many to Many relation through junction table. For instance, I have three tables, Jobs , Eqtypes and the junction table Eqtype_jobs . I want to relate some Eqtypes to a current Job using simple activeform using multiple select dropDownList . The following is the code that I have in, the controller and the view: //the controller

问题 ok, so I have a database comprising of two tables, products and suppliers. All suppliers fill in a form and their data is then stored in the suppliers table, and the products table contains a list of all of the products, so when the supplier fills in the form, he can choose as many products as he wishes as I use jQuery JSON and AJAX to get the list of all of the products and then populate a drop down list with all of them in it, which can then be cloned as many times as is needed. The problem

问题 I am building an application with an Article entity. Every article can have more Attribute (and one attribute can have many articles reffering to it). To manage the connection I am using link entity AttributeLink , so the connection is one-to-many-to-one . The link entity has additional field to store the attribute value . I have built a form with collection that works well. In fact, the solution worked fine and saved all the values correctly. When I went to style the form to look better, the

问题 I need to create a many-to-many table relationship in which the elements of one table are shared by the elements of a second table. I've read the multitude of similar posts, but I'm clearly still wrong somewhere. I've reduced my problem to this simple example. I have two tables: Beverages and Ingredients. I want the Ingredients to be shared among the Beverages. Is the problem how I've created the bridge table? (Can I do without a bridge table?) Or is the problem in how I'm managing the data