Search Results

Search found 6628 results on 266 pages for 'foreign keys'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 42/266 | < Previous Page | 38 39 40 41 42 43 44 45 46 47 48 49  | Next Page >

  • 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)

    Read the article

  • Non-normalized association with legacy tables in Rails and ActiveRecord

    - by Thomas Holmström
    I am building a Rails application accessing a legacy system. The data model contains Customers which can have one or more Subscriptions. A Subscription always belong to one and only one Customer. Though not needed, this association is represented through a join table "subscribes", which do not have an id column: Column | Type | Modifiers -----------------+---------+----------- customer_id | integer | not null subscription_id | integer | not null I have this coded as a has_and_belongs_to_many declarations in both Customer and Subscription class Customer < Activerecord::Base has_and_belongs_to_many :subscriptions, :join_table => "subscribes", :foreign_key => "customer_id", :association_foreign_key => "subscription_id" end class Subscription < Activerecord::Base has_and_belongs_to_many :customers, :join_table => "subscribes", :foreign_key => "subscription_id", :association_foreign_key => "customer_id" end The problem I have is that there can only ever be one customer for each subscription, not many, and the join table will always contain at most one row with a certain customer_id. And thus, I don't want the association "customers" on a Subscription which returns an array of (at most one) Customer, I really do want the relation "customer" which returns the Customer associated. Is there any way to force ActiveRecord to make this a 1-to-N relation even though the join table itself seems to make it an N-to-M relation? --Thomas

    Read the article

  • How to design this simple database?

    - by Vafello
    I have 2 tables - one storing user information (id, username, password) and the second one storing information about events (id, name, description, date, username(represents the user who created the event)). I would like to implement 'favourite events' functionality. This would allow the user to store his favourite events and later display them in a list. I am not sure how to implement this in terms of design. I need a simple solution. Something like storing the IDs of favourite events in a field in the user table. I am using mysql and php. Can anyone point me to the right direction?

    Read the article

  • Help needed with Linq To Sql Query

    - by fearofawhackplanet
    I have the concept of valid/ordered transitions. So for example, it's not possible to move to status In progress from status Complete. Current and Next in table StatusTransition are FK (StatusType.Id). The Linq generator has created the following relations: Child Property Name: StatusTransitions1 Parent Property Name: StatusType1 Participating Properties: StatusType.Id -> StatusTransition.Next Child Property Name: StatusTransitions Parent Property Name: StatusType Participating Properties: StatusType.Id -> StatusTransition.Current I'm normally ok with Linq but I'm having difficulty getting the list of valid Next StatusTypes from the Current status. public List<StatusType> GetValidStatusTransitions(int statusId) { // trying to write something like the following // (obviously not correct) return _statusRepository .Where(s => s.Id == statusId) .Next.StatusTypes; }

    Read the article

  • Multiple has_many's of the same model

    - by Koning Baard
    I have these models: Person has_many :messages_form_person, :foreign_key => :from_user_id, :class_name => :messages has_many :messages_to_person, :foreign_key => :to_user_id, :class_name => :messages Message belongs_to :to_person, :foreign_key => :to_user_id, :class_name => :person belongs_to :from_person, :foreign_key => :to_user_id, :class_name => :person And this view: person#show <% @person.messages_to_person.each do |message| %> <%=h message.title %> <% end %> But I get this error: TypeError in People#show Showing app/views/people/show.html.erb where line #26 raised: can't convert Symbol into String Extracted source (around line #26): 23: <%=h @person.biography %> 24: </p> 25: 26: <% @person.messages_to_person.each do |message| %> 27: 28: <% end %> 29: I basicly want that people can send eachother messages. Can anyone help me? Thanks.

    Read the article

  • Sql Server problems reading columns with a foreigh key

    - by illdev
    I have a weird situation, where simple queries seem to never finish for instance SELECT top 100 ArticleID FROM Article WHERE ProductGroupID=379114 returns immediately SELECT top 1000 ArticleID FROM Article WHERE ProductGroupID=379114 never returns SELECT ArticleID FROM Article WHERE ProductGroupID=379114 never returns SELECT top 1000 ArticleID FROM Article returns immediately by 'returning' I mean 'in query analyzer the green check mark appears and it says "Query executed successfully"'. I sometimes get the rows painted to the grid in qa, but still the query goes on waiting for my client to time out - 'sometimes': SELECT ProductGroupID AS Product23_1_, ArticleID AS ArticleID1_, ArticleID AS ArticleID18_0_, Inventory_Name AS Inventory3_18_0_, Inventory_UnitOfMeasure AS Inventory4_18_0_, BusinessKey AS Business5_18_0_, Name AS Name18_0_, ServesPeople AS ServesPe7_18_0_, InStock AS InStock18_0_, Description AS Descript9_18_0_, Description2 AS Descrip10_18_0_, TechnicalData AS Technic11_18_0_, IsDiscontinued AS IsDisco12_18_0_, Release AS Release18_0_, Classifications AS Classif14_18_0_, DistributorName AS Distrib15_18_0_, DistributorProductCode AS Distrib16_18_0_, Options AS Options18_0_, IsPromoted AS IsPromoted18_0_, IsBulkyFreight AS IsBulky19_18_0_, IsBackOrderOnly AS IsBackO20_18_0_, Price AS Price18_0_, Weight AS Weight18_0_, ProductGroupID AS Product23_18_0_, ConversationID AS Convers24_18_0_, DistributorID AS Distrib25_18_0_, type AS Type18_0_ FROM Article AS articles0_ WHERE (IsDiscontinued = '0') AND (ProductGroupID = 379121) shows this behavior. I have no idea what is going on. Probably select is broken ;) Anyone can tell me how to handle such a situation? More info, anyone?

    Read the article

  • 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?

    Read the article

  • Symfony 1.4: Deleting a sfGuardUser

    - by Tom
    Hi, I'm having some trouble with the following... I have a sfGuardUser table set up normally, and it has a one-to-one relationship with a Profile table, which contains some additional user info. When a user wants to delete themselves from the site, I'd like to retain their info in the Profile table for various purposes BUT delete the sfGuardUser in order to keep that table cleaner/shorter (not just set it to inactive). I was under the impression that I could set the FK in the Profile table to NULL and then delete the sfGuardUser, but it seems the FK-constraint fails. Indeed, it seems I can't delete either and the queries fail: If I try to delete the sfGuardUser, the Profile table will have an invalid FK If I try to delete a Profile, the sfGuardUser will have an invalid FK Other than leaving outdated sfGuardUsers and Profiles in these tables, or having to use a cascaded delete to get rid of both, can anyone tell me if there's any other way around this? Thank you.

    Read the article

  • Doctrine: How to traverse from an entity to another 'linked' entity?

    - by ropstah
    I'm loading 3 different tables using a cross-join in Doctrine_RawSql. This brings me back the following object: User -> User class (doctrine base class) Settings -> DoctrineCollection of Setting User_Settings -> DoctrineCollection of User_Setting The object above is the result of a many-to-many relationship between User and Setting where User_Setting acts as a reference table. User_Setting also contains another field named value. This obviously contains the value of the corresponding Setting. All good so far, however the Settings and User_Settings properties of the returned User object are in no way linked to each other (apart from the setting_id field ofcourse). Is there any direct way to traverse directly from the Settings property to the corresponding User_Settings property? This is the corresponding query: $sets = new Doctrine_RawSql(); $sets->select('{us.*}, {s.*}, {uset.*}') ->from('(User us CROSS JOIN Setting s) LEFT JOIN User_Setting uset ON us.user_id = uset.user_id AND s.setting_id = uset.setting_id') ->addComponent('us', 'User us') ->addComponent('uset', 'us.User_Setting uset') ->addComponent('s', 'us.Setting s') ->where('s.category_id = ? AND us.usr_auto_key = ?',array(1, 1)); $sets = $sets->execute();

    Read the article

  • MySQL - Find entries that refer to a specified index.

    - by Conor H
    Hi, So I have a booking system where I have a 'lesson_type' table with 'lesson_type_id' as PK. I have a constraint in place here so I can't delete a lesson_type if there are bookings made for that lesson_type. I would like to be able to determine if this lesson_type_id is being referred to by any entries in the bookings table (or any other table for that matter) so I can notify the user gracefully. i.e. not have a mysql error be thrown when they try and delete a record. What kind of query would I use for this? Thanks.

    Read the article

  • MySQL/PHP: How to insert logged in user id into another table that is gathering data from a form tha

    - by Lisa
    For the first time I am needing to join information from two tables and am quite nervous about doing it without any advice first. Basically, I am building a secure site that is accessed by authorised users. I have my login table with user_id, username, password Once the user is on the site, they have the option of inputting data into another table called input. At the moment this table only captures the information that is entered, not the user_id or username of the inputter. I would like the form to be able to input the user_id and/or username from the login table into the input table. Please could somebody talk me through this process? I am sure that once this is amended, I will then be able to use the table to only allow the logged in user to access the information that he or she have inputted, is that correct? Many thanks

    Read the article

  • 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...

    Read the article

  • How to retrieve all keys (or values) from a std::map?

    - by Owen
    This is one of the possible ways I come out: struct RetrieveKey { template <typename T> typename T::first_type operator()(T keyValuePair) const { return keyValuePair.first; } }; map<int, int> m; vector<int> keys; // Retrieve all keys transform(m.begin(), m.end(), back_inserter(keys), RetrieveKey()); // Dump all keys copy(keys.begin(), keys.end(), ostream_iterator<int>(cout, "\n")); Of course, we can also retrieve all values from the map by defining another functor RetrieveValues. Is there any other way to achieve this easily? (I'm always wondering why std::map does not include a member function for us to do so.)

    Read the article

  • Django: getting the list of related records for a list of objects

    - by Silver Light
    Hello! I have two models related one-to many: class Person(models.Model): name = models.CharField(max_length=255); surname = models.CharField(max_length=255); age = models.IntegerField(); class Dog(models.Model): name = models.CharField(max_length=255); owner = models.ForeignKey('Person'); I want to output a list of persons below each person a list of dogs he has. Here's how I can do it: in view: persons = Person.objects.all()[0:100]; in template: {% for p in persons %} {{ p.name }} has dogs:<br /> {% for d in persons.dog_set.all %} - {{ d.name }}<br /> {% endfor %} {% endfor %} But if I do it like that, Django will execute 101 SQL queries which is very inefficient. I tried to make a custom manager, which will get all the persons, then all the dogs and links them in python, but then I can't use paginator (my another question: http://stackoverflow.com/questions/2532475/django-paginator-raw-sql-query ) and it looks quite ugly. Is there a more graceful way doing this?

    Read the article

  • Entity framework Update fails when object is linked to a missing child

    - by McKay
    I’m having trouble updating an objects child when the object has a reference to a nonexising child record. eg. Tables Car and CarColor have a relationship. Car.CarColorId CarColor.CarColorId If I load the car with its color record like so this var result = from x in database.Car.Include("CarColor") where x.CarId = 5 select x; I'll get back the Car object and it’s Color object. Now suppose that some time ago a CarColor had been deleted but the Car record in question still contains the CarColorId value. So when I run the query the Color object is null because the CarColor record didn’t exist. My problem here is that when I attach another Color object that does exist I get a Store update, insert error when saving. Car.Color = newColor Database.SaveChanges(); It’s like the context is trying to delete the nonexisting color. How can I get around this?

    Read the article

  • Importing data and keeping ids and relationships

    - by Justin Hamade
    I am working on cleaning up a mess that another programmer started. The created 2 identical databases for different locations but that obviously caused major issues. They are using cakePHP and there are quite a few relationships. I am pretty sure I will have to write a script to import that data from on DB to the other and keep all the relationships but was wondering if there is an easier way to do it.

    Read the article

  • sphinx and languages other than English

    - by Tsf
    I found in http://svn.python.org/projects/doctools/trunk/sphinx/locale support for several languages that can be used in Sphinx but I did not find the instructions on how to install it: which files should be downloaded and installed in which directories? Any hint would be appreciated.

    Read the article

  • How do I make the F-keys work in byobu on 12.04, for midnight commander (mc), htop, etc?

    - by Jorge Castro
    I use byobu with the tmux backend on my 12.04 server. I'd like to use the midnight commander shortcut keys with it, but the F keys don't work. I've seen some posts on the issues here: https://bugs.launchpad.net/byobu/+bug/386363 https://answers.launchpad.net/byobu/+question/127610 but they are out of date and don't seem to work for newer versions of byobu. How can I either work around this or use MC in a way that works better?

    Read the article

  • Script to create or drop all primary keys now on TechNet Wiki.

    - by John Paul Cook
    I posted my script to create or drop all primary keys on the TechNet Wiki. You can find it at http://social.technet.microsoft.com/wiki/contents/articles/script-to-create-or-drop-all-primary-keys.aspx . I first published the script here in 2009 and I've always wanted a way for the community to enhance it or correct it. The TechNet Wiki makes that possible. Visit the Wiki and see if you like this approach to publishing scripts....(read more)

    Read the article

  • SDL doesn't detect Arrow Keys

    - by Scott
    I am working through the SDL tutorials over at http://lazyfoo.net/SDL_tutorials/index.php and I'm stuck on tutorial 8 where I'm working with key presses. I'm using the following code: //Our Main application loop while(!quit){ if(SDL_PollEvent(&curEvents)){ if(curEvents.type == SDL_QUIT){ quit = true; } //If a key was pressed if( curEvents.type == SDL_KEYDOWN ) { //Set the proper message surface switch( curEvents.key.keysym.sym ) { case SDLK_UP: message = upMessage; break; case SDLK_DOWN: message = downMessage; break; case SDLK_LEFT: message = leftMessage; break; case SDLK_RIGHT: message = rightMessage; break; default: message = TTF_RenderText_Solid(font, "Unknown Key", textColor); break; } } } if( message != NULL ) { //Apply the background to the screen applySurface( 0, 0, background, screen ); //Apply the message centered on the screen applySurface( ( SCREEN_WIDTH - message->w ) / 2, ( SCREEN_HEIGHT - message->h ) / 2, message, screen ); //Null the surface pointer message = NULL; } //Update the screen if( SDL_Flip( screen ) == -1 ) { return 1; } } Where works fine, the default case is reached, for everything BUT pressing the arrow keys. I was wondering if someone could spot what I'm doing wrong.

    Read the article

  • ASP.NET MVC Page - Dropdown control doesn't function with Keyboard Arrow Keys

    - by Rita
    Hi I have a page that has a Dropdown control (ddlDeliveryMethod). So that when the user selects particular option from the Dropdown(using MOUSE), the respective Div ID's are loaded. But instead of Mouse, if we simply use the arrow keys from Keyboard, the respective DIV ID's are not showing. Is there any workaround for this. Appreciate your responses. Here is my code: // based on Delivery method, display the respective fields $("#ddlDeliveryMethod").change(function() { $('#divRegisteredMail').hide(); $('#divRegisteredEmail').hide(); $('#divRegisteredFax').hide(); $('#divSaveForFuture').hide(); switch ($("#ddlDeliveryMethod ").val()) { case ' -- Select one -- ': break; case 'Email': $('#divRegisteredEmail').show(); break; case 'Mail': $('#divRegisteredMail').show(); break; case 'Fax': $('#divRegisteredFax').show(); break; default: caption = "default"; break; } });

    Read the article

  • Database relationships using phpmyAdmin (composite keys)

    - by Cool Hand Luke UK
    Hi, I hope this question is not me being dense. I am using phpmyAdmin to create a database. I have the following four tables. Don't worry about that fact place and price are optional they just are. Person (Mandatory) Item (Mandatory) Place (Optional) Price (Optional) Item is the main table. It will always have person linked. * I know you do joins in mysql for the tables. If I want to link the tables together I could use composite keys (using the ids from each table), however is this the most correct way to link the tables? It also means item will have 5 ids including its own. This all cause null values (apparently a big no no, which I can understand) because if place and price are optional and are not used on one entry to the items table I will have a null value there. Please help! Thanks in advance. I hope this makes sense.

    Read the article

  • Apply shortcut keys to sliverlight page

    - by sankar
    Hi.. In application requirement is as follows.. In the Silverlight child page(Usercontrol, when you click menu item )open page it requires to fill some data then for saving we have Save button for cancel it we have Cancel button. Here i am looking for Saving data i need to use ShortCut Keys(Ctrl + S). If i write the following code in KeyDown event it is not Functioning well, because Generally we punch the 'Ctrl' key in Presssed mode and then we punch the "S" key here if i punch 'Ctrl' key is not released then it is not working.. Otherwise ie. if punch "Ctrl" key then release it then punch "S" it is working fine.. //Code //int count=0;--Global--- protected override void OnKeyDown(KeyEventArgs e) { base.OnKeyDown(e); if (e.Key == Key.Ctrl) { count = 1; } string str = e.Key.ToString(); if (count >0 && str == "S") { //MessageBox.Show("Saved"); //Saving the data count = 0; } } I am looking for it works on With "Ctrl" key is in pressed mode please look into this... Thanks

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 38 39 40 41 42 43 44 45 46 47 48 49  | Next Page >