Search Results

Search found 2729 results on 110 pages for 'fk relationship'.

Page 15/110 | < Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >

  • Select * from 'many to many' SQL relationship

    - by Rampant Creative Group
    I'm still learning SQL and my brain is having a hard time with this one. Say I have 3 tables: teams players and teams_players as my link table All I want to do is run a query to get each team and the players on them. I tried this: SELECT * FROM teams INNER JOIN teams_players ON teams.id = teams_players.team_id INNER JOIN players ON teams_players.player_id = players.id But it returned a separate row for each player on each team. Is JOIN the right way to do it or should I be doing something else? ----------------------------------------- Edit Ok, so from what I'm hearing, this isn't necessarily a bad way to do it. I'll just have to group the data by team while I'm doing my loop. I have not yet tried the modified SQL statements provided, but I will today and get back to you. To answer the question about structure - I guess I wasn't thinking about the returned row structure which is part of what lead to my confusion. In this particular case, each team is limited to 4 players (or less) so I guess the structure that would be helpful to me is something like the following: teams.id, teams.name, players.id, players.name, players.id, players.name, players.id, players.name, players.id, players.name, 1 Team ABC 1 Jim 2 Bob 3 Ned 4 Roy 2 Team XYZ 2 Bob 3 Ned 5 Ralph 6 Tom

    Read the article

  • Complex SQL query, one to many relationship

    - by Ethan
    Hey SO, I have a query such that I need to get A specific dog All comments relating to that dog The user who posted each comment All links to images of the dog the user who posted each link I've tried a several things, and can't figure out quite how to work it. Here's what I have (condensed so you don't have to wade through it all): SELECT s.dog_id, s.name, c.comment, c.date_added AS comment_date_added, u.username AS comment_username, u.user_id AS comment_user_id, l.link AS link, l.date_added AS link_date_added, u2.username AS link_username, u2.user_id AS link_user_id FROM dogs AS d LEFT JOIN comments AS c ON c.dog_id = d.dog_id LEFT JOIN users AS u ON c.user_id = u.user_id LEFT JOIN links AS l ON l.dog_id = d.dog_id LEFT JOIN users AS u2 ON l.user_id = u2.user_id WHERE d.dog_id = '1' It's sorta close to working, but it'll only return me the first comment, and the first link all as one big array with all the info i requested. The are multiple comments and links per dog, so I need it to give me all the comments and all the links. Ideally it'd return an object with dog_id, name, comments(an array of the comments), links(an array of the links) and then comments would have a bunch of comments, date_added, username, and user_id and links would have a bunch of links with link, date_added, username and user_id. It's got to work even if there are no links or comments. I learned the basics of mySQL somewhat recently, but this is pretty far over my head. Any help would be wonderful. Thanks!

    Read the article

  • Edit the opposite side of a many to many relationship with django generic form

    - by Ed
    I have two models: class Actor(models.Model): name = models.CharField(max_length=30, unique = True) event = models.ManyToManyField(Event, blank=True, null=True) class Event(models.Model): name = models.CharField(max_length=30, unique = True) long_description = models.TextField(blank=True, null=True) In a previous question: http://stackoverflow.com/questions/2503243/django-form-linking-2-models-by-many-to-many-field, I created an EventForm with a save function: class EventForm(forms.ModelForm): class Meta: model = Event def save(self, commit=True): instance = forms.ModelForm.save(self) instance.actors_set.clear() for actor in self.cleaned_data['actors']: instance.actors_set.add(actors) return instance This allowed me to add m2m links from the other side of the defined m2m connection. Now I want to edit the entry. I've been using a generic function: def generic_edit(request, modelname, object_id): modelname = modelname.lower() form_class = form_dict[modelname] return update_object(request, form_class = form_class, object_id = object_id, template_name = 'createdit.html' ) but this pulls in all the info except the many-to-many selections saved to this object. I think I need to do something similar to this: http://stackoverflow.com/questions/1700202/editing-both-sides-of-m2m-in-admin-page, but I haven't figured it out. How do I use the generic update_object to edit the other side of many-to-many link?

    Read the article

  • Using attr_accessible in a join model with has_many :through relationship

    - by Paulo Oliveira
    I have a USER that creates a COMPANY and become an EMPLOYEE in the process. The employees table has an :user_id and a :company_id. class User has_many :employees has_many :companies, :through => :employees class Employee belongs_to :user belongs_to :company attr_accessible :active class Company has_many :employees has_many :users, :through => employees Pretty basic. But here's the thing, the resource EMPLOYEE has other attributes than its foreign keys, like the boolean :active. I would like to use attr_accessible, but this causes some problems. The attribute :user_id is set right, but :company_id is nil. @user.companies << Company.new(...) Employee id:1 user_id:1 company_id:nil So my question is: if :user_id is set right, despite it is not an attr_accessible, why :company_id isn't set right just the same? It shouldn't be an attr_accessible. I'm using Rails 3.0.8, and have also tested with 3.0.7.

    Read the article

  • Deleting objects through foreign key relationship with T-SQL query

    - by LaserBeak
    Looking for a way to write the following LinQ to entities query as a T-SQL statement. repository.ProductShells.Where(x => x.ShellMembers.Any(sm => sm.ProductID == pid)).ToList().ForEach(x => repository.ProductShells.Remove(x)); The below is obviously not correct but I need it to delete respective ProductShell object where any ShellMember contains a ProductID equal to the passed in variable pid. I would presume this would involve a join statement to get the relevant ShellMembers. repository.Database.ExecuteSqlCommand("FROM Shellmembers WHERE ProductID={0} DELETE FK_ProductShell", pid); I have cascade delete enabled for the FK_ShellMembers_ProductShells foreign key, so when I delete the ProductShell it will delete all the ShellMembers that are associated with it. I am going to pass this statement to System.Data.Entity Database.ExecuteSqlCommand method.

    Read the article

  • Parent child class relationship design pattern

    - by Jeremy
    I have a class which has a list of child items. Is there a design pattern I can copy that I can apply to these classes so that I can access the parent instance from the child, and it enforces rules such as not being able to add the child to multiple parents, etc?

    Read the article

  • Minimizing SQL queries using join with one-to-many relationship

    - by Brian
    So let me preface this by saying that I'm not an SQL wizard by any means. What I want to do is simple as a concept, but has presented me with a small challenge when trying to minimize the amount of database queries I'm performing. Let's say I have a table of departments. Within each department is a list of employees. What is the most efficient way of listing all the departments and which employees are in each department. So for example if I have a department table with: id name 1 sales 2 marketing And a people table with: id department_id name 1 1 Tom 2 1 Bill 3 2 Jessica 4 1 Rachel 5 2 John What is the best way list all departments and all employees for each department like so: Sales Tom Bill Rachel Marketing Jessica John Pretend both tables are actually massive. (I want to avoid getting a list of departments, and then looping through the result and doing an individual query for each department). Think similarly of selecting the statuses/comments in a Facebook-like system, when statuses and comments are stored in separate tables.

    Read the article

  • java: relationship of the Runnable and Thread interfaces

    - by Karl Patrick
    I realize that the method run() must be declared because its declared in the Runnable interface. But my question comes when this class runs how is the Thread object allowed if there is no import call to a particular package? how does runnable know anything about Thread or its methods? does the Runnable interface extend the Thread class? Obviously I don't understand interfaces very well. thanks in advance. class PrimeFinder implements Runnable{ public long target; public long prime; public boolean finished = false; public Thread runner; PrimeFinder(long inTarget){ target = inTarget; if(runner == null){ runner = new Thread(this); runner.start() } } public void run(){ } }

    Read the article

  • T-SQL: Build Nested Set From Parent-Child Relationship

    - by Peder Rice
    I have a table that stores my Customer hierarchy with a nested set (due to the specific design of the application, I wasn't able to leverage just a Customer/Parent Customer mapping table). To simplify maintenance of this table, I've built a couple of stored procedures to handle moving nodes around and creating new nodes, but it's significantly more work than maintaining a Customer/Parent Customer table. Further, these structures are very fragile. So I'm looking for a way to have a Customer/Parent Customer table and then convert that table to a nested set on demand. Does anyone have a link to such an implementation?

    Read the article

  • PHP object parent/child recursion

    - by Damien
    I've got a parent-child OO relationship. Parent obejcts has many child objects and every child object knows about it's parent by reference. The parent can be a child too (basically its a tree). When i do a var_dump() on the root object it says ["parent"]=RECURSION many times and the generated description will be really long. I'm wondering if i do something wrong. If yes, i'm interested in the "best practice". Thanks for the help!

    Read the article

  • I would like to make a field part of a many to many relationship

    - by jona
    I have the following table called stores id store zip 1 Market 1 01569 2 Market 2 01551 3 Market 3 10468 4 Market 4 10435 Zip code table INSERT INTO `zip_codes` (`restaurants_locations_id`, `zip`, `state`, `latitude`, `longitude`, `city`, `full_state`) VALUES (1, '06001', 'CT', ' 41.789698', ' -72.86431', 'Avon', 'Connecticut'), (2, '06002', 'CT', ' 41.832798', ' -72.72642', 'Bloomfield', 'Connecticut'), (3, '06010', 'CT', ' 41.682249', ' -72.93365', 'Bristol', 'Connecticut'), (4, '06013', 'CT', ' 41.758415', ' -72.94642', 'Burlington', 'Connecticut'), (5, '06016', 'CT', ' 41.909097', ' -72.54393', 'Windsorville', 'Connecticut'), (6, '06018', 'CT', ' 42.023510', ' -73.31103', 'Canaan', 'Connecticut'), (7, '06019', 'CT', ' 41.834247', ' -72.89174', 'Canton', 'Connecticut'), etc.... what I want is to create a table which will connect the zip field in the stores tables where one store will be found in several zicodes... How would that table would look like? Thanks

    Read the article

  • What is the relationship between domNode and htmlelement?

    - by Turtle
    Hello, I am confused about the two terms. What is the difference in browser-side javascript programming? I use dojo as framework. And there is only the concept of domNode. But browser debugger always told me something as htmlelement. Are they just the same thing with different names, or with some subtle differences? Thanks.

    Read the article

  • Displaying a To-Many Relationship in a Table View

    - by DanF
    I've got an application I've been working on. There are projects and employees, projects can have several employees, employees can work on several projects. Right now I want selecting a project to display which employees are related to it, and allows me to add employees I select from another full-roster list. Somehow, this has proven more complicated, because (at least for now), selecting different projects still displays the same list of employees, as if all employees who'd been assigned to any project, belong to all of them. What part of Master-Detail am I missing?

    Read the article

  • SQL table relationship not showing up in visual studio

    - by PFranchise
    Hey, I made several tables and relationships using SQL server manager. I then imported them to visual studio and it all appeared in the correct form, except one of the relationships did not appear. I have checked everything I could think of and it is the exact same as the other relationships. If you know anything I can check, I would appreciate it. Thanks I am using the entity framework, visual studio 2010.

    Read the article

  • How to model a mutually exclusive relationship in sql server

    - by littlechris
    Hi, I have to add functionality to an existing application and I've run into a data situation that I'm not sure how to model. I am being restricted to the creation of new tables and code. If I need to alter the existing structure I think my client may reject the proposal..although if its the only way to get it right this is what I will have to do. I have an Item table that can me link to any number of tables, and these tables may increase over time. The Item can only me linked to one other table, but the record in the other table may have many items linked to it. Examples of the tables/entities being linked to are "Person", "Vehicle", "Building", "Office". These are all separate tables. Example of Items are "Pen", "Stapler", "Cushion", "Tyre", "A4 Paper", "Plastic Bag", "Poster", "Decoration" For instance a "Poster" may be allocated to a "Person" or "Office" or "Building". In the future if they add a "Conference Room" table it may also be added to that. My intital thoughts are: Item { ID, Name } LinkedItem { ItemID, LinkedToTableName, LinkedToID } The LinkedToTableName field will then allow me to identify the correct table to link to in my code. I'm not overly happy with this solution, but I can't quite think of anything else. Please help! :) Thanks!

    Read the article

  • TSQL, select values from large many-to-many relationship

    - by eugeneK
    I have two tables Publishers and Campaigns, both have similar many-to-many relationships with Countries,Regions,Languages and Categories. more info Publisher2Categories has publisherID and categoryID which are foreign keys to publisherID in Publishers and categoryID in Categories which are identity columns. On other side i have Campaigns2Categories with campaignID and categoryID columns which are foreign keys to campaignID in Campaigns and categoryID in Categories which again are identities. Same goes for Regions, Languages and Countries relationships I pass to query certain publisherID and want to get campaignIDs of Campaigns that have at least one equal to Publisher value from regions, countries, language or categories thanks

    Read the article

  • CakePHP hasMany relationship with multiple columns

    - by Muhammad Yasir
    Hi, I am using CakePHP framework to build a web application. The simplest form of my problem is this: I have a users table and a messages table with corresponding models. Messages are sent from a user to another user. So messages table has columns from_id and to_id in it, both referencing to id of users. I am able to link Message model to User model by using $belongsTo but I am unable to link User model with Message model (in reverse direction) by using $hasMany in the same manner. var $hasMany = array( 'From' => array( 'className' => 'Message', 'foreignKey' => 'from_id', 'dependent' => false, 'conditions' => '', 'fields' => '', 'order' => '', 'limit' => '', 'offset' => '', 'exclusive' => '', 'finderQuery' => '', 'counterQuery' => '' ), 'To' => array( 'className' => 'Message', 'foreignKey' => 'to_id', 'dependent' => false, 'conditions' => '', 'fields' => '', 'order' => '', 'limit' => '', 'offset' => '', 'exclusive' => '', 'finderQuery' => '', 'counterQuery' => '' ) ); What can do here? Any ideas? Thanks for any help.

    Read the article

  • Validations for a has_many/belongs_to relationship

    - by Craig Walker
    I have a Recipe model which has_many Ingredients (which in turn belongs_to Recipe). I want Ingredient to be existent dependent on Recipe; an Ingredient should never exist without a Recipe. I'm trying to enforce the presence of a valid Recipe ID in the Ingredient. I've been doing this with a validates :recipe, :presence => true (Rails 3) statement in Ingredient. This works fine if I save the Recipe before adding an Ingredient to it's ingredients collection. However, if I don't have explicit control over the saving (such as when I'm creating a Recipe and its Ingredients from a nested form) then I get an error: Ingredients recipe can't be blank I can get around this simply by dropping the presence validation on Ingredient.recipe. However, I don't particularly like this, as it means I'm working without a safety net. What is the best way to enforce existence-dependence in Rails? Things I'm considering (please comment on the wisdom of each): Adding a not-null constraint on the ingredients.recipe_id database column, and letting the database do the checking for me. A custom validation that somehow checks whether the Ingredient is in an unsaved recipe's ingredient collection (and thus can't have a recipe_id but is still considered valid).

    Read the article

  • getting hasMany records of a HABTM relationship

    - by charliefarley321
    I have tables: categories HABTM sculptures hasMany images from the CategoriesController#find() produces an array like so: array( 'Category' => array( 'id' => '3', 'name' => 'Modern', ), 'Sculpture' => array( (int) 0 => array( 'id' => '25', 'name' => 'Ami', 'material' => 'Bronze', 'CategoriesSculpture' => array( 'id' => '18', 'category_id' => '3', 'sculpture_id' => '25' ) ), (int) 1 => array( 'id' => '26', 'name' => 'Charis', 'material' => 'Bronze', 'CategoriesSculpture' => array( 'id' => '19', 'category_id' => '3', 'sculpture_id' => '26' ) ) ) ) I'd like to be able to get the images related to sculpture in the array as well if this is possible?

    Read the article

  • OpenAL device, buffer and context relationship

    - by Markus
    I'm trying to create an object oriented model to wrap OpenAL and have a little problem understanding the devices, buffers and contexts. From what I can see in the Programmer's Guide, there are multiple devices, each of which can have multiple contexts as well as multiple buffers. Each context has a listener, and the alListener*() functions all operate on the listener of the active context. (Meaning that I have to make another context active first if I wanted to change it's listener, if I got that right.) So far, so good. What irritates me though is that I need to pass a device to the alcCreateContext() function, but none to alGenBuffers(). How does this work then? When I open multiple devices, on which device are the buffers created? Are the buffers shared between all devices? What happens to the buffers if I close all open devices? (Or is there something I missed?)

    Read the article

  • ROR accepts_nested_attributes_for one to many relationship with selection

    - by bilash.saha
    I have two models Doctors and Questions like the follwong: Doctor Model class Doctor < ActiveRecord::Base has_many :questions has_many :brands accepts_nested_attributes_for :questions end Question model class Question < ActiveRecord::Base belongs_to :discipline belongs_to :doctor belongs_to :brand end Now you can clearly see that Doctor has many questions and brands and question belongs to doctor and brand.I want to add previously saved question to a doctor from doctors edit page. I want to remove them as well.How can I proceed ? I tried like : <%= form.fields_for :questions, question,:child_index => (question.new_record? ? "index_to_replace_with_js" : nil) do |question_form| %> <table> <tr> <td> <div class="label">Select Question</div> <%= question_form.collection_select :id, Question.all, :id, :title ,{:include_blank => true } %> </td> </tr> </table> but this doesnot works for me.Can you give me a solution with proper example ?

    Read the article

  • Inverse relationship of two variables

    - by Jam
    this one is maybe pretty stupid.. Or I am just exhausted or something, but I just cant seem to solve it.. Problem : two variables X and Y, value of Y is dependent on value of X. X can have values ranging from some value to some value (lets say from 0 to 250) and y can have different values (lets say from 0.1 to 1.0 or something..) - but it is inverse relatonship (what I mean is: if value of X is e.g. 250, then value of Y would be 0.1 and when X decreases up to 0, value of Y raises up to 1.0.. So how should I do it? lets say I have function: -- double computeValue (double X) { /computation/ return Y; } Also, is there some easy way to somehow make the scaling of the function not so linear? - For example when X raises, Y decreases slower at first but then more rapidly in the end.. (rly dont know how to say it but I hope you guys got it) Thanks in advance for this stupid question :/

    Read the article

  • How to create relationship between two tables with revisions using Entity Framework

    - by Chris Ridenour
    So I am in the process of redesigning a small database (and potentially a much larger one) but want to show the value of using revisions / history of the business objects. I am switching the data from Access to MSSQL 2008. I am having a lot of internal debate on what version of "revision history" to use in the design itself - and thought I had decided to add a "RevisionId" to all tables. With this design - adding a RevisionId to all tables we would like tracked - what would be the best way to create Navigational Properties and Relationships between two tables such as | Vendor | VendorContact | where a Vendor can have multiple contacts. The Contacts themselves will be under revision. Will it require custom extensions or am I over thinking this? Thanks in advance.

    Read the article

< Previous Page | 11 12 13 14 15 16 17 18 19 20 21 22  | Next Page >