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  • Formtastic with Mongoid embedded_in relations

    - by miah
    Is there any quick way to make a form for embeds_many-embedded_in relation? I have the following: class Team include Mongoid::Document field :name, :type => String embeds_many :players end class Player include Mongoid::Document embedded_in :team, :inverse_of => :players field :name, :type => String end I want to create a form for team with embedded editing for players. Seen https://github.com/bowsersenior/formtastic_with_mongoid_tutorial but "TODO" there.

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  • how to query with child relations to same table and order this correctly

    - by robertpnl
    Hi, Take this table: id name sub_id --------------------------- 1 A (null) 2 B (null) 3 A2 1 4 A3 1 The sub_id column is a relation to his owm table, to column ID. subid --- 0:1 --- id Now I have the problem to make a correctly SELECT query to show that the child rows (which sub_id is not null) directly selected under his parent row. So this must be a correctly order: 1 A (null) 3 A2 1 4 A3 1 2 B (null) A normal SELECT order the id. But how or which keyword help me to order this correctly? JOIN isn't possible I think because I want to get all the rows seperated. Because the rows will be displayed on a Gridview (ASP.Net) with EntityDataSource but the child rows must be displayed directly under his parent. Thank you.

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  • Help with active record relations

    - by Christian Fazzini
    class CreateActivities < ActiveRecord::Migration def self.up create_table :activities do |t| t.references :user t.references :media t.integer :artist_id t.string :type t.timestamps end end def self.down drop_table :activities end end class Fan < Activity belongs_to :user, :counter_cache => true end class Activity < ActiveRecord::Base belongs_to :user belongs_to :media belongs_to :artist, :class_name => 'User', :foreign_key => 'artist_id' end class User < ActiveRecord::Base has_many :activities has_many :fans end I tried changing my activity model too, without any success: class Activity < ActiveRecord::Base has_many :activities, :class_name => 'User', :foreign_key => 'user_id' has_many :activities, :class_name => 'User', :foreign_key => 'artist_id' end One thing to note. Activity is an STI. Fan inherits from Activity. In console, I do: # Create a fan object. User is a fan of himself fan = Fan.new => #<Fan id: nil, user_id: nil, media_id: nil, artist_id: nil, type: "Fan", comment: nil, created_at: nil, updated_at: nil> # Assign a user object fan.user = User.first => #<User id: 1, genre_id: 1, country_id: 1, .... # Assign an artist object fan.artist_id = User.first.id => 1 # Save the fan object fan.save! => true Activity.last => #<Fan id: 13, user_id: 1, media_id: nil, artist_id: 1, type: "Fan", comment: nil, created_at: "2010-12-30 08:41:25", updated_at: "2010-12-30 08:41:25"> Activity.last.user => #<User id: 1, genre_id: 1, country_id: 1, ..... But... Activity.last.artist => nil Why is Activity.last.artist returning nil?

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  • MATLAB: Automatic detection of relations between workspace variables through functions

    - by Peterstone
    Hi all, I´m trying to write a function what detect this relation between the variables I have got in the workspace: v1 - fft(v2) = 0 Where v1, v2 are variables of my workspace. Sometimes I need to know which variables have a certain numerical relation. If I have thirty, I don´t want to be looking for this relation in "manual way", just itroducing a sentence for each pair of different variables. I would like a function in which I introuce (or I modify this function every time I need it) the sentence (for instance what I wrote before) and the function show me the pair of variables a I am looking for. Does anyone know how to do it? Thank you so much!

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  • CSS and JavaScript relations ?

    - by Anil Namde
    I have table cell which has class "cellActive". Which has following defination .cellActive{background:"#DDDDDD"} Now i am trying to read the background color property for the cell and it comes null/"". var bgColor = cell.style.backgroundColor; // returning "" Is that something mistake on my part of its by behavior. If CSS class is assigning CSS to element can't we read its value in JS ? Does this mean that if we are not assigning property directly to the element we cant get it if in case its inheriting it ?

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  • Confusions with CSS and JavaScript relations ?

    - by Anil Namde
    I have table cell which has class "cellActive". Which has following defination .cellActive{background:"#DDDDDD"} Now i am trying to read the background color property for the cell and it comes null/"". var bgColor = cell.style.backgroundColor; // returning "" Is that something mistake on my part of its by behavior. If CSS class is assigning CSS to element can't we read its value in JS ? Does this mean that if we are not assigning property directly to the element we cant get it if in case its inheriting it ?

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  • Rails: Design Pattern to Store Order of Relations

    - by ChrisInCambo
    Hi, I have four models: Customer, QueueRed, QueueBlue, QueueGreen. The Queue models have a one to many relationship with customers A customer must always be in a queue A customer can only be in one queue at a time A customer can change queues We must be able to find out the customers current position in their respective queue In an object model the queues would just have an array property containing customers, but ActiveRecord doesn't have arrays. In a DB I would probably create some extra tables just to handle the order of the stories in the queue. My question is what it the best way to model the relationship in ActiveRecord? Obviously there are many ways this could be done, but what is the best or the most in line with how ActiveRecord should be used? Cheers, Chris

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  • Enable export to XML via HTTP on a large number of models with child relations

    - by Vasil
    I've a large number of models (120+) and I would like to let users of my application export all of the data from them in XML format. I looked at django-piston, but I would like to do this with minimum code. Basically I'd like to have something like this: GET /export/applabel/ModelName/ Would stream all instances of ModelName in applabel together with it's tree of related objects . I'd like to do this without writing code for each model. What would be the best way to do this?

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  • Django: remove all m2m relations

    - by pistacchio
    Hi, if I have two simple models: class Tag(models.Model): name = models.CharField(max_length=100) class Post(models.Model): title = models.CharField(max_length=100) tags = models.ManyToManyField(Tag, blank=True) given a Post object with a number of Tags added to it, I know hot to remove any of them, but how to do a mass remove (remove all)? Thanks

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  • How to solve recursion relations in mathematica efficiently?

    - by Qiang Li
    I have a recursion to solve for. f(m,n)=Sum[f[m - 1, n - 1 - i] + f[m - 3, n - 5 - i], {i, 2, n - 2*m + 2}] + f[m - 1, n - 3] + f[m - 3, n - 7] f(0,n)=1, f(1,n)=n However, the following mma code is very inefficient f[m_, n_] := Module[{}, If[m < 0, Return[0];]; If[m == 0, Return[1];]; If[m == 1, Return[n];]; Return[Sum[f[m - 1, n - 1 - i] + f[m - 3, n - 5 - i], {i, 2, n - 2*m + 2}] + f[m - 1, n - 3] + f[m - 3, n - 7]];] It takes unbearably long to compute f[40,20]. Could anyone please suggest an efficient way of doing this? Many thanks!

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  • doctrine default values and relations

    - by Skirmantas
    Concept: Lets say we have table Properties with columns id and name (lets say with some predefined values: "Good" "Better" "Best"). Another table Users has column property_id with many to one relation on Properties (property_id = id). Users has default value on property_id, lets say 1 which means "Good". We might have another table analogue to Users however with default property, lets say "Better". What I need is ability to change default value for Users or other tables in administrator's panel. In mysql I can set default value for column like this: ALTER TABLE <Table> CHANGE <Column> DEFAULT <NEW_DEFAULT_VALUE> I can retrieve default value: SELECT DEFAULT(<Column>) FROM <Table> LIMIT 1 Is it possible to achieve this concept with Doctrine? What I actually need is such method in my table class: class UserTable extend Doctrine_Table { /* ... */ getDefaultProperty() { } setDefaultProperty($value) { /* $value can be either integer or Doctrine_Record */ } }

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  • A better understanding of the relations beetween database tables

    - by Nistor Alexandru
    Hi I am trying to get a better understanding of relational databases and there is something that I keep bumping into and don't understand.Let's take this two tables: In this case Login.ID is the primary key with auto_increment set and Profile.ID_LOGIN is the Foreign KEY.When a user is created and it's username and password is stored in the login database does the ID coresponding to the curesnt username and password get automaticly added into ID_LOGIN or do I have to create an SQL statement to do this? If I have to create a SQL statement how should I aproach adding the ID_LOGIN to make sure I am adding it corectly?

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  • Dynamic class_name for has_many relations

    - by vooD
    I'm trying to make has_many relation with dynamic class_name attribute class Category < ActiveRecord::Base has_many :ads, :class_name => ( lambda { return self.item_type } ) end or class Category < ActiveRecord::Base has_many :ads, :class_name => self.item_type end But i got errors: can't convert Proc into String or undefined method `item_type' for #<Class:0xb62c6c88> Thank you for any help!

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  • Trying to make models in Kohana, relations problem.

    - by Asaf
    I have a table of Hits, Articles and Categories Now, a Hit belongs_to an Article/Category (depends on where it was done). so I have a column on Hits table with the name 'parenttype' That tells me 'Article' or 'Category'. I wrote in the Hit model (extends ORM) protected $_belongs_to= array( 'page' => array('model'=> $this->parenttype) ); Now it complains about $this-parenttype not being expected?

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  • Question between aggregations, compositions, references (arrow) and simple link (nothing) relations within UML2 ?

    - by Rushino
    Hello, I have some questions regarding relations between aggregations, compositions, references (arrow) and simple link (nothing) relations within UML2 ? If A - B - C each have composition relationship. Are the root responsable of creation and destruction of the object B and C ? What aggregations have that the simple link or references doesn't ? What make them different ? Thanks. Edit: The question was a bit unclear and not objective. I edited it.

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  • JPA joined column allow every value...

    - by Fabio Beoni
    I'm testing JPA, in a simple case File/FileVersions tables (Master/Details), with OneToMany relation, I have this problem: in FileVersions table, the field "file_id" (responsable for the relation with File table) accepts every values, not only values from File table. How can I use the JPA mapping to limit the input in FileVersion.file_id only for values existing in File.id? My class are File and FileVersion: FILE CLASS @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name="FILE_ID") private Long id; @Column(name="NAME", nullable = false, length = 30) private String name; //RELATIONS ------------------------------------------- @OneToMany(mappedBy="file", fetch=FetchType.EAGER) private Collection <FileVersion> fileVersionsList; //----------------------------------------------------- FILEVERSION CLASS @Id @GeneratedValue(strategy = GenerationType.IDENTITY) @Column(name="VERSION_ID") private Long id; @Column(name="FILENAME", nullable = false, length = 255) private String fileName; @Column(name="NOTES", nullable = false, length = 200) private String notes; //RELATIONS ------------------------------------------- @ManyToOne(fetch=FetchType.EAGER) @JoinColumn(name="FILE_ID", referencedColumnName="FILE_ID", nullable=false) private File file; //----------------------------------------------------- and this is the FILEVERSION TABLE CREATE TABLE `JPA-Support`.`FILEVERSION` ( `VERSION_ID` bigint(20) NOT NULL AUTO_INCREMENT, `FILENAME` varchar(255) NOT NULL, `NOTES` varchar(200) NOT NULL, `FILE_ID` bigint(20) NOT NULL, PRIMARY KEY (`VERSION_ID`), KEY `FK_FILEVERSION_FILE_ID` (`FILE_ID`) ) ENGINE=MyISAM AUTO_INCREMENT=4 DEFAULT CHARSET=latin1

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  • django model relation definition

    - by Laurent Luce
    Hello, Let say I have 3 models: A, B and C with the following relations. A can have many B and many C. B can have many C Is the following correct: class A(models.Model): ... class B(models.Model): ... a = ForeignKey(A) class C(models.Model): ... a = ForeignKey(A) b = ForeignKey(B)

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  • Un blogueur dévoile un iPhone tournant sous Android, alors que les relations entre Google et Apple s

    Un blogueur dévoile un iPhone tournant sous Android, alors que les relations entre Google et Apple sont au plus mal Alors que la situation est des plus tendues entre Apple et Google, les deux concurrents se retrouvent réunis sur un même appareil. Un informaticien passionné a en effet trouvé le moyen de faire tourner son iPhone sous Android. Cela fait déjà un an qu'il essaie et expérimentent divers techniques pour arriver à cette cohabitation de systèmes, avec plus ou moins de succès. Il dit avoir perdu du temps en se laissant distraire par le jailbreak. Grâce au dual boot, ils peuvent passer le l'OS iPhone à celui de Google. Planetbeing, le blogueur derrière cette initiative, a publié aujourd'hui une v...

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  • Creating multiple relationships in rails with same datatypes

    - by Lowgain
    What I am trying to do is kind of like this: I have datatypes "user" and "article" for instance. I want to have relationships between these two, but in more than one way. So for instance, I'd like to let a user "like" or "bookmark" an article. So I need to have two relations in the database, one for users liking the article, and one for users bookmarking, so making a "user_article" table for instance won't be sufficient, correct? What is the best way of going about doing this?

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  • Using Include() with inherited entities problem

    - by Peter Stegnar
    In EF eager loading related entities is easy. But I'm having difficulties including inherited entities when loading data using table-per-type model. This is my model: Entities: ArticleBase (base article entity) ArticleSpecial (inherited from ArticleBase) UserBase (base user entity) UserSpecial (inherited from UserBase) Image Relations are as shown on the image (omitting many columns): In reality my users are always of type UserSpecial, since UserBase is used in another application, thus we can share credentials. That's the only reason I have two separate tables. UserBase table can't be changed in any way shape or form, because the other app would break. Question How am I suppose to load ArticleSpecial with both CreatedBy and EditedBy set, so that both are of type UserSpecial (that defines Image relation)? I've tried (unsuccessfully though) these options: 1. Using lambda expressions: context.ArticleBases .OfType<ArticleSpecial>() .Include("UserCreated.Image") .Include("UserEdited.Image"); In this case the problem is that both CreatedBy and EditedBy are related to UserBase, that doesn't define Image navigation. So I should somehow cast these two to UserSpecial type like: context.ArticleBases .OfType<ArticleSpecial>() .Include("UserCreated<UserSpecial>.Image") .Include("UserEdited<UserSpecial>.Image"); But of course using generics in Include("UserCreated<UserSpecial>.Image") don't work. 2. I have tried using LINQ query var results = from articleSpecial in ctx.ArticleBase.OfType<ArticleSpecial>() join created in ctx.UserBase.OfType<UserSpecial>().Include("Image") on articleSpecial.UserCreated.Id equals created.Id join edited in ctx.UserBase.OfType<UserSpecial>().Include("Image") on articleSpecial.UserEdited.Id equals edited.Id select articleSpecial; In this case I'm only getting ArticleSpecial object instances without related properties being set. I know I should select those somehow, but I don't know how? Select part in my LINQ could be changed to something like select new { articleSpecial, articleSpecial.UserCreated, articleSpecial.UserEdited }; but images are still not loaded into my context. My joins in this case are barely used to filter out articleSpecial results, but they don't load entities into context (I suppose). Can anybody provide any help regarding this problem? I think it's not so uncommon.

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  • Database structure - To join or not to join

    - by Industrial
    Hi! We're drawing up the database structure with the help of mySQL Workbench for a new app and the number of joins required to make a listing of the data is increasing drastically as the many-to-many relationships increases. The application will be quite read-heavy and have a couple of hundred thousand rows per table. The questions: Is it really that bad to merge tables where needed and thereby reducing joins? Should we start looking at horizontal partitioning? (in conjunction with merging tables) Is there a better way then pivot tables to take care of many-to-many relationships? We discussed about instead storing all data in serialized text columns and having the application make the sorting instead of the database, but this seems like a very bad idea, even though that the database will be heavily cached. What do you think? Thanks!

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  • SQL database problems with addressbook table design

    - by Sebastian Hoitz
    Hello! I am writing a addressbook module for my software right now. I have the database set up so far that it supports a very flexible address-book configuration. I can create n-entries for every type I want. Type means here data like 'email', 'address', 'telephone' etc. I have a table named 'contact_profiles'. This only has two columns: id Primary key date_created DATETIME And then there is a table called contact_attributes. This one is a little more complex: id PK #profile (Foreign key to contact_profiles.id) type VARCHAR describing the type of the entry (name, email, phone, fax, website, ...) I should probably change this to a SET later. value Text (containing the value for the attribute). I can now link to these profiles, for example from my user's table. But from here I run into problems. At the moment I would have to create a JOIN for each value that I want to retrieve. Is there a possibility to somehow create a View, that gives me a result with the type's as columns? So right now I would get something like #profile type value 1 email [email protected] 1 name Sebastian Hoitz 1 website domain.tld But it would be nice to get a result like this: #profile email name website 1 [email protected] Sebastian Hoitz domain.tld The reason I do not want to create the table layout like this initially is, that there might always be things to add and I want to be able to have multiple attributes of the same type. So do you know if there is any possibility to convert this dynamically? If you need a better description please let me know. Thank you!

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  • Non Working Relationship

    - by Dominik K.
    Hello everyone, I got a problem with cake's model architecture. I got a Users-Model and a Metas-Model. Here are the model codes: Users: <?php class User extends AppModel { var $name = 'User'; var $validate = array( 'username' => array('notempty'), 'email' => array('email'), 'password' => array('notempty') ); var $displayField = 'username'; var $hasMany = array( 'Meta' => array( 'className' => 'Meta', 'foreignKey' => 'user_id' ) ); } ?> and the Metas Model: <?php class Meta extends AppModel { var $name = 'Meta'; //The Associations below have been created with all possible keys, those that are not needed can be removed var $belongsTo = array( 'User' => array( 'className' => 'User', 'foreignKey' => 'user_id', 'required' => true ) ); } ?> So now the question is why do I not get the Meta data into the User array? Should I get it in the Auth object? Or where can I work with the meta data? hope you can help me! Have a nice Day! Dom

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