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  • NHibernate ManyToMany Relationship Cascading AllDeleteOrphan StackOverflowException

    - by Chris
    I have two objects that have a ManyToMany relationship with one another through a mapping table. Though, when I try to save it, I get a stack overflow exception. The following is the code for the mappings: //EventMapping.cs HasManyToMany(x => x.Performers).Table("EventPerformer").Inverse().Cascade.AllDeleteOrphan().LazyLoad().ParentKeyColumn("EventId").ChildKeyColumn("PerformerId"); //PerformerMapping.cs HasManyToMany<Event>(x => x.Events).Table("EventPerformer").Inverse().Cascade.AllDeleteOrphan().LazyLoad().ParentKeyColumn("PerformerId").ChildKeyColumn("EventId"); When I change the performermapping.cs to Cascade.None() I get rid of the exception but then my Event Object doesn't have the performer I associate with it. //In a unit test, paraphrased event.Performers.Add(performer); //Event eventRepository.Save<Event>(event); eventResult = eventRepository.GetById<Event>(event.id); //Event eventResult.Performers[0]; //is null, should have performer in it How should I be writing this properly? Thanks

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  • Silverlight error-handling conventions: There is no relationship between onSilverlightError and Repo

    - by rasx
    When I see the call System.Windows.Browser.HtmlPage.Window.Eval (which is evil) in ReportErrorToDOM (in App.xaml.cs) this shows me that it has no relationship to onSilverlightError. So what kind of JavaScript-based scenario calls onSilverlightError? When will onSilverlightError definitely be needed? What are Silverlight error-handling conventions in general? This is a very important comment by Erik Monk but needs more detail: There are 2 kinds of terminal errors in Silverlight. 1) Managed errors (hit the managed Application_UnhandledException method). Note that some errors may not even get to this point. If the managed infrastructure can't be loaded for some reason (out of memory error maybe...), you won't get this kind of error. Still, if you can get it, you can use a web service (or the CLOG project) to communicate it back to the server. 2) Javascript errors.

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  • SQL: many-to-many relationship, IN condition

    - by Maarten
    I have a table called transactions with a many-to-many relationship to items through the items_transactions table. I want to do something like this: SELECT "transactions".* FROM "transactions" INNER JOIN "items_transactions" ON "items_transactions".transaction_id = "transactions".id INNER JOIN "items" ON "items".id = "items_transactions".item_id WHERE (items.id IN (<list of items>)) But this gives me all transactions that have one or more of the items in the list associated with it and I only want it to give me the transactions that are associated with all of those items. Any help would be appreciated.

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  • has_many through a habtm relationship in Rails

    - by macek
    I'm trying to define a has_many X, :through => Y where Y is a habtm relationship. Rails is throwing a fit about this. See comment in user model: class User < ActiveRecord::Base has_many :posts # I want to display a list of all tags this user is involved in has_many :tags, :through => :posts # ERROR end class Post < ActiveRecord::Base has_and_belongs_to_many :tags end class Tag < ActiveRecord::Base has_and_belongs_to_many :posts end What can I do to fix this?

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  • validates_uniqueness_of with HABTM relationship

    - by jeffshantz
    I've got a HABTM relationship between two models: Publication and Author. I want to ensure that one cannot create a publication with the same title, year, and author list. However, if I try something like this: class Publication < ActiveRecord::Base validates_uniqueness_of :title, :scope => [:year, :authors] end This obviously won't work since there is no authors column. Can this be done with validates_uniqueness_of, or do I need a custom validator? Thank you.

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  • Cannot set g:checkbox to off for a child on one-to-many relationship

    - by icon911
    Got a weird issue with g:checkbox not being saved when its switched from on to off for a child in one-to-many relationship. For example: class Parent { Boolean enabled static hasMany = [children: Child] static constraints = { enabled(blank: true, nullable: true) } } class Child { Boolean enabled static belongsTo = [parent: Parent] static constraints = { enabled(blank: true, nullable: true) } } Posting to Parent controller true/false values will work for Parent: <g:checkBox name="enabled" value="${parentInstance?.enabled}"/> However, not for Child! When posting to Parent controller I can only go from false to true, trying to change from true to false again will not work: <g:each in="${parentInstance.children}" status="i" var="child"> <g:checkBox name="child[${i}].enabled" value="${child?.enabled}" /> </g:each> That seems to be a bug. Any ideas? Thanks.

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  • Core Data Relationships in pre-populated SQLite database

    - by Cardinal
    Hi All, I'm new to Core Data. Currently I have following tables on hand: tbl_teahcer tbl_student tbl_course tbl_student_course_map ----------- ----------- ---------- ---------------------- teacher_id student_id course_id student_id name name name course_id teahcer_id And I'm going to make the xcdatamodel as below: Course Teacher ------ ------- name name teacher <<----------> courses students <<---| | Student | ------- | name |----->> courses My questions are as follows: As I'd like to create TableView for Cource Entity, is it a must to create the Inverse Relationship from Teacher to Course, and Student to Course? What is the beneit for having the Inverse Relationship? I got some pre-defined data on hand, and I'd like to create a SQLite storage for pre-populated source. How can I set up the relationships (both directions) in SQLite? Thank you for your help! Regards, Cardinal

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  • ordering an acts_as_tree relationship

    - by timpone
    I have a Category class that is defined like this: class Catergoy < ActiveRecord::Base acts_as_tree :parent_id I'd like the ordering to be by the position value which is a float such that: category-1 category-2, parent_id=1, position=0.5 category-3, parent_id=2, category-4, parent_id=1, position=1 How would I specify this? I tried acts_as_tree :parent_id :order => :position acts_as_tree :parent_id, :order => :position but these are not working. Any ideas how to specify this relationship? Or if I'm missing something else? thx in advance

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  • Entity Framework 4 CTP 5 POCO - Many-to-many configuration, insertion, and update?

    - by Saxman
    I really need someone to help me to fully understand how to do many-to-many relationship with Entity Framework 4 CTP 5, POCO. I need to understand 3 concepts: How to config my model to indicates some tables are many-to-many. How to properly do insert. How to properly do update. Here are my current models: public class MusicSheet { [Key] public int ID { get; set; } public string Title { get; set; } public string Key { get; set; } public virtual ICollection<Author> Authors { get; set; } public virtual ICollection<Tag> Tags { get; set; } } public class Author { [Key] public int ID { get; set; } public string Name { get; set; } public string Bio { get; set; } public virtual ICollection<MusicSheet> MusicSheets { get; set; } } public class Tag { [Key] public int ID { get; set; } public string TagName { get; set; } public virtual ICollection<MusicSheet> MusicSheets { get; set; } } As you can see, the MusicSheet can have many Authors or Tags, and an Author or Tag can have multiple MusicSheets. Again, my questions are: What to do on the EntityTypeConfiguration to set the relationship between them as well as mapping to an table/object that associates with the many-to-many relationship. How to insert a new music sheets (where it might have multiple authors or multiple tags). How to update a music sheet. For example, I might set TagA, TagB to MusicSheet1, but later I need to change the tags to TagA and TagC. It seems like I need to first check to see if the tags already exists, if not, insert the new tag and then associate it with the music sheet (so that I doesn't re-insert TagA?). Or this is something already handled by the framework? Thank you very much. I really hope to fully understand it rather than just doing it without fully understand what's going on. Especially on #3.

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  • One to two relationship in Doctrine with YAML

    - by Jeremy DeGroot
    I'm working on my first Symfony project with Doctrine, and I've run into a hitch. I'm trying to express a game with two players. The relationship I want to have is PlayerOne and PlayerTwo each being keyed to an ID in the Users table. This is part of what I've got so far: Game: actAs: { Timestampable:- } columns: id: { type: integer, notnull: true, unique: true } startDate: { type: timestamp, notnull: true } playerOne: { type: integer, notnull: true } playerTwo: { type: integer, notnull: true } winner: { type: integer, notnull:true, default:0 } relations: User: { onUpdate: cascade, local: playerOne, foreign: id} User: { onUpdate: cascade, local: playerTwo, foreign: id} That doesn't work. It builds fine, but the SQL it generates only includes a constraint for playerTwo. I've tried a few other things: User: { onUpdate: cascade, local: [playerOne, playerTwo], foreign: id} Also: User: [{ onUpdate: cascade, local: playerOne, foreign: id}, { onUpdate: cascade, local: playerTwo, foreign: id}] Those last two throw errors when I try to build. Is there anyone out there who understands what I'm trying to do and can help me achieve it?

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  • What is the relationship between IRimTable and PersistenceStore?

    - by Martin
    The BlackBerry Desktop API has the interface IRimTable which apparently maps an "application database" on a BlackBerry device to a virtual structure (i.e, IRimTable has IRimRecords, each of which has IRimField) that developer can browse the handheld device data when it is connected to a desktop computer. Meanwhile, applications in the handheld device can store its data in PersistenceStore databases. The point where I'm stuck is the PersistenceStore API doesn't define any Table or Records or Fields. Does anybody knows what is the relationship between these two classes? And how does the mapping work (if at all) ?

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  • Ruby on Rails - Create Entity with Relationship

    - by SooDesuNe
    I'm new to rails, so be nice. I'm building a "rolodex" type application, and this question is about the best way to handle creating an entity along with several relationship entities at the same time. For (a contrived) example: My application will have a Person model, which has_one Contact_Info model. On the create.html.erb page for Person it makes sense for the user of my appliction to create the person, and the contact_info at the same time. It doesn't seem right to include details for creating a contact directly in the create view/controller for person. What's the rails way to handle this?

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  • One to One relationship in MySQL

    - by Botto
    I'm trying to make a one to one relationship in a MySQL DB. I'm using the InnoDB engine and the basic table looks like this: CREATE TABLE `foo` ( `fooID` INT(11) NOT NULL PRIMARY KEY AUTO_INCREMENT, `name` TEXT NOT NULL ) CREATE TABLE `bar` ( `barName` VARCHAR(100) NOT NULL, `fooID` INT(11) NOT NULL PRIMARY KEY, CONSTRAINT `contact` FOREIGN KEY (`fooID`) REFERENCES `foo`(`fooID`) ) Now once I have set up these I alter the foo table so that the fooID also becomes a foreign key to the fooID in bar. The only issue I am facing with this is that there will be a integrity issue when I try to insert into either. I would like some help, thanks.

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  • Linq2Entities: Update relationship?

    - by Poku
    Hey, How do i create a new row in a table which have a relationship with another table? I have an Employees table and a EmployeeProjects table. One Employee can have 1-* EmployeeProjects. Now i want to create a new EmployeeProject which relates to an Employee. How do i do this? Here is want i have tried so far: var ep = new EmployeeProjects(); ep.JobNo = jobNo; employee.EmployeeProjects.Add(ep); var originalEmployee = GetEmployee(employee.Id); _entities.ApplyPropertyChanges(originalEmployee.EntityKey.EntitySetName, employee); _entities.SaveChanges();

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  • Select in a many-to-many relationship in MySQL

    - by Joff Williams
    I have two tables in a MySQL database, Locations and Tags, and a third table LocationsTagsAssoc which associates the two tables and treats them as a many-to-many relationship. Table structure is as follows: Locations --------- ID int (Primary Key) Name varchar(128) LocationsTagsAssoc ------------------ ID int (Primary Key) LocationID int (Foreign Key) TagID int (Foreign Key) Tags ---- ID int (Primary Key) Name varchar(128) So each location can be tagged with multiple tagwords, and each tagword can be tagged to multiple locations. What I want to do is select only Locations which are tagged with all of the tag names supplied. For example: I want all locations which are tagged with both "trees" and "swings". Location "Park" should be selected, but location "Forest" should not. Any insight would be appreciated. Thanks!

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  • Custom OData operation / customize EF model to hide join table in many-to-many relationship

    - by AC
    I've got a data model that has two tables with a join table for a many to many relationship & creating an OData service to expose the data for CRUD ops in a Silverlight app. What I'd like to do is abstract the join table from the service. I'm not sure if the best way to do this would be in the model (using EF in .NET3.5SP1) or if I should do it with a custom service operation. If I do it in the EF model (not sure how I'd do this), then the OOTB WCF Data Service stuff would make it easy to say [..]/Courses(1)/Modules ... otherwise I'd have to create a custom operation to do this. Is it possible to do this in the EF model and if so, how does that work?

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  • ruby on rails has_many through relationship

    - by BennyB
    Hi i'm having a little trouble with a has_many through relationship for my app and was hoping to find some help. So i've got Users & Lectures. Lectures are created by one user but then other users can then "join" the Lectures that have been created. Users have their own profile feed of the Lectures they have created & also have a feed of Lectures friends have created. This question however is not about creating a lecture but rather "Joining" a lecture that has been created already. I've created a "lecturerelationships" model & controller to handle this relationship between Lectures & the Users who have Joined (which i call "actives"). Users also then MUST "Exit" the Lecture (either by clicking "Exit" or navigating to one of the header navigation links). I'm grateful if anyone can work through some of this with me... I've got: Users.rb model Lectures.rb model Users_controller Lectures_controller then the following model lecturerelationship.rb class lecturerelationship < ActiveRecord::Base attr_accessible :active_id, :joinedlecture_id belongs_to :active, :class_name => "User" belongs_to :joinedlecture, :class_name => "Lecture" validates :active_id, :presence => true validates :joinedlecture_id, :presence => true end lecturerelationships_controller.rb class LecturerelationshipsController < ApplicationController before_filter :signed_in_user def create @lecture = Lecture.find(params[:lecturerelationship][:joinedlecture_id]) current_user.join!(@lecture) redirect_to @lecture end def destroy @lecture = Lecturerelationship.find(params[:id]).joinedlecture current_user.exit!(@user) redirect_to @user end end Lectures that have been created (by friends) show up on a users feed in the following file _activity_item.html.erb <li id="<%= activity_item.id %>"> <%= link_to gravatar_for(activity_item.user, :size => 200), activity_item.user %><br clear="all"> <%= render :partial => 'shared/join', :locals => {:activity_item => activity_item} %> <span class="title"><%= link_to activity_item.title, lecture_url(activity_item) %></span><br clear="all"> <span class="user"> Joined by <%= link_to activity_item.user.name, activity_item.user %> </span><br clear="all"> <span class="timestamp"> <%= time_ago_in_words(activity_item.created_at) %> ago. </span> <% if current_user?(activity_item.user) %> <%= link_to "delete", activity_item, :method => :delete, :confirm => "Are you sure?", :title => activity_item.content %> <% end %> </li> Then you see I link to the the 'shared/join' partial above which can be seen in the file below _join.html.erb <%= form_for(current_user.lecturerelationships.build(:joinedlecture_id => activity_item.id)) do |f| %> <div> <%= f.hidden_field :joinedlecture_id %> </div> <%= f.submit "Join", :class => "btn btn-large btn-info" %> <% end %> Some more files that might be needed: config/routes.rb SampleApp::Application.routes.draw do resources :users do member do get :following, :followers, :joined_lectures end end resources :sessions, :only => [:new, :create, :destroy] resources :lectures, :only => [:create, :destroy, :show] resources :relationships, :only => [:create, :destroy] #for users following each other resources :lecturerelationships, :only => [:create, :destroy] #users joining existing lectures So what happens is the lecture comes in my activity_feed with a Join button option at the bottom...which should create a lecturerelationship of an "active" & "joinedlecture" (which obviously are supposed to be coming from the user & lecture classes. But the error i get when i click the join button is as follows: ActiveRecord::StatementInvalid in LecturerelationshipsController#create SQLite3::ConstraintException: constraint failed: INSERT INTO "lecturerelationships" ("active_id", "created_at", "joinedlecture_id", "updated_at") VALUES (?, ?, ?, ?) Also i've included my user model (seems the error is referring to it) user.rb class User < ActiveRecord::Base attr_accessible :email, :name, :password, :password_confirmation has_secure_password has_many :lectures, :dependent => :destroy has_many :lecturerelationships, :foreign_key => "active_id", :dependent => :destroy has_many :joined_lectures, :through => :lecturerelationships, :source => :joinedlecture before_save { |user| user.email = email.downcase } before_save :create_remember_token validates :name, :presence => true, :length => { :maximum => 50 } VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i validates :email, :presence => true, :format => { :with => VALID_EMAIL_REGEX }, :uniqueness => { :case_sensitive => false } validates :password, :presence => true, :length => { :minimum => 6 } validates :password_confirmation, :presence => true def activity # This feed is for "My Activity" - basically lectures i've started Lecture.where("user_id = ?", id) end def friendactivity Lecture.from_users_followed_by(self) end # lECTURE TO USER (JOINING) RELATIONSHIPS def joined?(selected_lecture) lecturerelationships.find_by_joinedlecture_id(selected_lecture.id) end def join!(selected_lecture) lecturerelationships.create!(:joinedlecture_id => selected_lecture.id) end def exit!(selected_lecture) lecturerelationships.find_by_joinedlecture_id(selected_lecture.id).destroy end end Thanks for any and all help - i'll be on here for a while so as mentioned i'd GREATLY appreciate someone who may have the time to work through my issues with me...

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  • How do I specify a null relation in SQLAlchemy?

    - by Jesse
    Not sure what the correct title for this question should be. I have the following schema: Matters have a one-many relationship to WorkItems. WorkItems have a one-one (or one-zero) relationship to LineItems. I am trying to create the following relation between Matters and WorkItems Matter.unbilled_work_items = orm.relation(WorkItem, primaryjoin = (Matter.id == WorkItem.matter_id) and (WorkItem.line_item_id == None), foreign_keys = [WorkItem.matter_id, WorkItem.line_item_id], viewonly=True ) This throws: AttributeError: '_Null' object has no attribute 'table' That seems to be saying that the second clause in the primaryjoin returns an object of type _Null, but it seems to be expecting something with a "table" attribute. This seems like it should be pretty straightforward to me, am I missing something obvious?

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  • Representing parent-child relationships in SharePoint lists

    - by Chris Farmer
    I need to create some functionality in our SharePoint app that populates a list or lists with some simple hierarchical data. Each parent record will represent a "submission" and each child record will be a "submission item." There's a 1-to-n relationship between submissions and submission items. Is this practical to do in SharePoint? The only types of list relationships I've done so far are lookup columns, but this seems a bit different. Also, once such a list relationship is established, then what's the best way to create views on this kind of data. I'm almost convinced that it'd be easier just to write this stuff to an external database, but I'd like to give SharePoint a shot in order to take advantage of the automated search capabilities.

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  • Selecting one object from a one-to-many relationship in Hibernate

    - by Nick Thomson
    I have two tables: Job job_id, <other data> Job_Link job_link_id, job_id, start_timestamp, end_timestamp, <other data> There may be multiple records in Job_Link specifying the same job_id with the start_timestamp and end_timestamps to indicate when those records are considered "current", it is guaranteed that start_timestamp and end_timestamp will not overlap. We have entities for both the Job and Job_Link tables and defining a one-to-many relationship to load all the job_links wouldn't be a problem. However we'd like to avoid that and have a single job_link item in the Job entity that will contain only the "current" Job_Link object. Is there any way to achive that?

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  • Cakephp: Designpattern for creation of models in hasMany relationship

    - by Chris
    I have two Models: Car and Passenger. Car hasMany Passenger Passenger belongsTo Car I managed to create add functionailty for each model and managed to resolve the hasMany relationship between them. Now I'm trying to create a addCar function and view that allows the user to create a new car and automatically generate Passengers. I thought of something like this The view asks the user enter the car information The view has some field that allows to temporarly add new passengers and remove remove them When the user saves the new car, the entities for the passengers are created, the entity for the car is created and the passengers are linked to the car. If the user decides to cacnel everything, the DB remains unchanged. Now my question is: What is the best way to do this? Is there a pattern / tutorial to follow for such a entity and associated subentity creation? To clarify: The passengers associated with each car do not exist prior to the existence of the car.

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  • Table per subclass inheritance relationship: How to query against the Parent class without loading a

    - by Arthur Ronald F D Garcia
    Suppose a Table per subclass inheritance relationship which can be described bellow (From wikibooks.org - see here) Notice Parent class is not abstract @Entity @Inheritance(strategy=InheritanceType.JOINED) public class Project { @Id private long id; // Other properties } @Entity @Table(name="LARGEPROJECT") public class LargeProject extends Project { private BigDecimal budget; } @Entity @Table(name="SMALLPROJECT") public class SmallProject extends Project { } I have a scenario where i just need to retrieve the Parent class. Because of performance issues, What should i do to run a HQL query in order to retrieve the Parent class and just the Parent class without loading any subclass ???

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  • Save or update for FK relationship Sqlalchemy

    - by Alex
    I've googled, but haven't been able to find the answer to this seemingly simple question. I have two relations, a customer and an order. Each order is associated to a single cusomter, and therefore has a FK relationship to the customer table. The customer relation only stores customer names, and I have set a unique constraint on the customer table barring duplicate names. Let's say I create a new order instance and set a customer for the order. Something like: order_instance.customer = Customer("customer name") When I save the order instance, SqlAlchemy will complain if a customer with this name already exists in the customer table. How do I specify to SqlAlchemy to insert into the customer table if a customer with this name doesn't already exist, or just ignore (or even update) to the customer relation? I don't really want to have to check each time if a customer with some name already exists...

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  • Many-to-one relationship in SQLAlchemy

    - by Arrieta
    This is a beginner-level question. I have a catalog of mtypes: mtype_id name 1 'mtype1' 2 'mtype2' [etc] and a catalog of Objects, which must have an associated mtype: obj_id mtype_id name 1 1 'obj1' 2 1 'obj2' 3 2 'obj3' [etc] I am trying to do this in SQLAlchemy by creating the following schemas: mtypes_table = Table('mtypes', metadata, Column('mtype_id', Integer, primary_key=True), Column('name', String(50), nullable=False, unique=True), ) objs_table = Table('objects', metadata, Column('obj_id', Integer, primary_key=True), Column('mtype_id', None, ForeignKey('mtypes.mtype_id')), Column('name', String(50), nullable=False, unique=True), ) mapper(MType, mtypes_table) mapper(MyObject, objs_table, properties={'mtype':Relationship(MType, backref='objs', cascade="all, delete-orphan")} ) When I try to add a simple element like: mtype1 = MType('mtype1') obj1 = MyObject('obj1') obj1.mtype=mtype1 session.add(obj1) I get the error: AttributeError: 'NoneType' object has no attribute 'cascade_iterator' Any ideas?

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