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  • 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?

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  • Same data being returned by linq for 2 different executions of a stored procedure?

    - by Paul
    Hello I have a stored procedure that I am calling through Entity Framework. The stored procedure has 2 date parameters. I supply different argument in the 2 times I call the stored procedure. I have verified using SQL Profiler that the stored procedure is being called correctly and returning the correct results. When I call my method the second time with different arguments, even though the stored procedure is bringing back the correct results, the table created contains the same data as the first time I called it. dtStart = 01/08/2009 dtEnd = 31/08/2009 public List<dataRecord> GetData(DateTime dtStart, DateTime dtEnd) { var tbl = from t in db.SP(dtStart, dtEnd) select t; return tbl.ToList(); } GetData((new DateTime(2009, 8, 1), new DateTime(2009, 8, 31)) // tbl.field1 value = 45450 - CORRECT GetData(new DateTime(2009, 7, 1), new DateTime(2009, 7, 31)) // tbl.field1 value = 45450 - WRONG 27456 expected Is this a case of Entity Framework being clever and caching? I can't see why it would cache this though as it has executed the stored procedure twice. Do I have to do something to close tbl? using Visual Studio 2008 + Entity Framework. I also get the message "query cannot be enumerated more than once" a few times every now and then, am not sure if that is relevant? FULL CODE LISTING namespace ProfileDataService { public partial class DataService { public static List<MeterTotalConsumpRecord> GetTotalAllTimesConsumption(DateTime dtStart, DateTime dtEnd, EUtilityGroup ug, int nMeterSelectionType, int nCustomerID, int nUserID, string strSelection, bool bClosedLocations, bool bDisposedLocations) { dbChildDataContext db = DBManager.ChildDataConext(nCustomerID); var tbl = from t in db.GetTotalConsumptionByMeter(dtStart, dtEnd, (int) ug, nMeterSelectionType, nCustomerID, nUserID, strSelection, bClosedLocations, bDisposedLocations, 1) select t; return tbl.ToList(); } } } /// CALLER List<MeterTotalConsumpRecord> _P1Totals; List<MeterTotalConsumpRecord> _P2Totals; public void LoadData(int nUserID, int nCustomerID, ELocationSelectionMethod locationSelectionMethod, string strLocations, bool bIncludeClosedLocations, bool bIncludeDisposedLocations, DateTime dtStart, DateTime dtEnd, ReportsBusinessLogic.Lists.EPeriodType durMainPeriodType, ReportsBusinessLogic.Lists.EPeriodType durCompareToPeriodType, ReportsBusinessLogic.Lists.EIncreaseReportType rptType, bool bIncludeDecreases) { ///Code for setting properties using parameters.. _P2Totals = ProfileDataService.DataService.GetTotalAllTimesConsumption(_P2StartDate, _P2EndDate, EUtilityGroup.Electricity, 1, nCustomerID, nUserID, strLocations, bIncludeClosedLocations, bIncludeDisposedLocations); _P1Totals = ProfileDataService.DataService.GetTotalAllTimesConsumption(_StartDate, _EndDate, EUtilityGroup.Electricity, 1, nCustomerID, nUserID, strLocations, bIncludeClosedLocations, bIncludeDisposedLocations); PopulateLines() //This fills up a list of objects with information for my report ready for the totals to be added PopulateTotals(_P1Totals, 1); PopulateTotals(_P2Totals, 2); } void PopulateTotals(List<MeterTotalConsumpRecord> objTotals, int nPeriod) { MeterTotalConsumpRecord objMeterConsumption = null; foreach (IncreaseReportDataRecord objLine in _Lines) { objMeterConsumption = objTotals.Find(delegate(MeterTotalConsumpRecord t) { return t.MeterID == objLine.MeterID; }); if (objMeterConsumption != null) { if (nPeriod == 1) { objLine.P1Consumption = (double)objMeterConsumption.Consumption; } else { objLine.P2Consumption = (double)objMeterConsumption.Consumption; } objMeterConsumption = null; } } } }

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  • IQueryable and lazy loading

    - by Nelson
    I'm having a hard time determining the best way to handle this... With Entity Framework (and L2S), LINQ queries return IQueryable. I have read various opinions on whether the DAL/BLL should return IQueryable, IEnumerable or IList. Assuming we go with IList, then the query is run immediately and that control is not passed on to the next layer. This makes it easier to unit test, etc. You lose the ability to refine the query at higher levels, but you could simply create another method that allows you to refine the query and still return IList. And there are many more pros/cons. So far so good. Now comes Entity Framework and lazy loading. I am using POCO objects with proxies in .NET 4/VS 2010. In the presentation layer I do: foreach (Order order in bll.GetOrders()) { foreach (OrderLine orderLine in order.OrderLines) { // Do something } } In this case, GetOrders() returns IList so it executes immediately before returning to the PL. But in the next foreach, you have lazy loading which executes multiple SQL queries as it gets all the OrderLines. So basically, the PL is running SQL queries "on demand" in the wrong layer. Is there any sensible way to avoid this? I could turn lazy loading off, but then what's the point of having this "feature" that everyone was complaining EF1 didn't have? And I'll admit it is very useful in many scenarios. So I see several options: Somehow remove all associations in the entities and add methods to return them. This goes against the default EF behavior/code generation and makes it harder to do some composite (multiple entity) LINQ queries. It seems like a step backwards. I vote no. If we have lazy loading anyway which makes it hard to unit test, then go all the way and return IQueryable. You'll have more control farther up the layers. I still don't think this is a good option because IQueryable ties you to L2S, L2E, or your own full implementation of IQueryable. Lazy loading may run queries "on demand", but doesn't tie you to any specific interface. I vote no. Turn off lazy loading. You'll have to handle your associations manually. This could be with eager loading's .Include(). I vote yes in some specific cases. Keep IList and lazy loading. I vote yes in many cases, only due to the troubles with the others. Any other options or suggestions? I haven't found an option that really convinces me.

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  • 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.

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  • 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?

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  • Classes to Entities; Like-class inheritence problems

    - by Stacey
    Beyond work, some friends and I are trying to build a game of sorts; The way we structure some of it works pretty well for a normal object oriented approach, but as most developers will attest this does not always translate itself well into a database persistent approach. This is not the absolute layout of what we have, it is just a sample model given for sake of representation. The whole project is being done in C# 4.0, and we have every intention of using Entity Framework 4.0 (unless Fluent nHibernate can really offer us something we outright cannot do in EF). One of the problems we keep running across is inheriting things in database models. Using the Entity Framework designer, I can draw the same code I have below; but I'm sure it is pretty obvious that it doesn't work like it is expected to. To clarify a little bit; 'Items' have bonuses, which can be of anything. Therefore, every part of the game must derive from something similar so that no matter what is 'changed' it is all at a basic enough level to be hooked into. Sounds fairly simple and straightforward, right? So then, we inherit everything that pertains to the game from 'Unit'. Weights, Measures, Random (think like dice, maybe?), and there will be other such entities. Some of them are similar, but in code they will each react differently. We're having a really big problem with abstracting this kind of thing into a database model. Without 'Enum' support, it is proving difficult to translate into multiple tables that still share a common listing. One solution we've depicted is to use a 'key ring' type approach, where everything that attaches to a character is stored on a 'Ring' with a 'Key', where each Key has a Value that represents a type. This works functionally but we've discovered it becomes very sluggish and performs poorly. We also dislike this approach because it begins to feel as if everything is 'dumped' into one class; which makes management and logical structure difficult to adhere to. I was hoping someone else might have some ideas on what I could do with this problem. It's really driving me up the wall; To summarize; the goal is to build a type (Unit) that can be used as a base type (Table per Type) for generic reference across a relatively global scope, without having to dump everything into a single collection. I can use an Interface to determine actual behavior so that isn't too big of an issue. This is 'roughly' the same idea expressed in the Entity Framework.

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  • Symfony2: validate an object that is not an entity

    - by Marronsuisse
    I am using CraueFormFlowBundle to have a multiple page form, and am trying to do some validation on some of the fields but can't figure out how to do this. The object that needs to be validated isn't an Entity, which is causing me trouble. I tried adding a collectionConstraint in the getDefaultOption function of my form type class, but this doesn't work as I get the "Expected argument of type array or Traversable and ArrayAccess" error. I tried with annotations in my object class, but they don't seem to be taken into account. Are annotations taken into account if the class isn't an entity? (i set enable_annotations to true) Anyway, what is the proper way to do this? Basically, I just want to validate that "age" is an integer... class PoemDataCollectorFormType extends AbstractType { public function buildForm(FormBuilder $builder, array $options) { switch ($options['flowStep']) { case 6: $builder->add('msgCategory', 'hidden', array( )); $builder->add('msgFIB','text', array( 'required' => false, )); $builder->add('age', 'integer', array( 'required' => false, )); break; } } public function getDefaultOptions(array $options) { $options = parent::getDefaultOptions($options); $options['flowStep'] = 1; $options['data_class'] = 'YOP\YourOwnPoetBundle\PoemBuilder\PoemDataCollector'; $options['intention'] = 'my_secret_key'; return $options; } } EDIT: add code, handle validation with annotations As Cyprian, I was pretty sure that using annotations should work, however it doesn't... Here is how I try: In my Controller: public function collectPoemDataAction() { $collector = $this->get('yop.poem.datacollector'); $flow = $this->get('yop.form.flow.poemDataCollector'); $flow->bind($collector); $form = $flow->createForm($collector); if ($flow->isValid($form)) { .... } } In my PoemDataCollector class, which is my data class (service yop.poem.datacollector): class PoemDataCollector { /** * @Assert\Type(type="integer", message="Age should be a number") */ private $age; } EDIT2: Here is the services implementation: The data class (PoemDataCollector) seems to be linked to the flow class and not to the form.. Is that why there is no validation? <service id="yop.poem.datacollector" class="YOP\YourOwnPoetBundle\PoemBuilder\PoemDataCollector"> </service> <service id="yop.form.poemDataCollector" class="YOP\YourOwnPoetBundle\Form\Type\PoemDataCollectorFormType"> <tag name="form.type" alias="poemDataCollector" /> </service> <service id="yop.form.flow.poemDataCollector" class="YOP\YourOwnPoetBundle\Form\PoemDataCollectorFlow" parent="craue.form.flow" scope="request"> <call method="setFormType"> <argument type="service" id="yop.form.poemDataCollector" /> </call> </service> How can I do the validation while respecting the craueFormFlowBundle guidelines? The guidelines state: Validation groups To validate the form data class a step-based validation group is passed to the form type. By default, if getName() of the form type returns registerUser, such a group is named flow_registerUser_step1 for the first step. Where should I state my constraint to use those validation groups..? I tried: YOP\YourOwnPoetBundle\PoemBuilder\Form\Type\PoemDataCollectorFormType: properties: name: - MinLength: { limit: 5, message: "Your name must have at least {{ limit }} characters.", groups: [flow_poemDataCollector_step1] } sex: - Type: type: integer message: Please input a number groups: [flow_poemDataCollector_step6] But it is not taken into acount.

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  • 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?

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  • 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.

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  • 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(){ } }

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  • 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!

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  • 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

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  • Preventing EF4 ConstraintException when invoking TryUpdateModel

    - by twk
    Given following ASP.NET MVC controller code: [HttpPost] public ActionResult Create(FormCollection collection) { string[] whitelist = new []{ "CompanyName", "Address1", "Address2", ... }; Partner newPartner = new Partner(); if (TryUpdateModel(newPartner, whitelist, collection)) { var db = new mainEntities(); db.Partners.AddObject(newPartner); db.SaveChanges(); return RedirectToAction("Details/" + newPartner.ID); } else { return View(); } } The problem is with the Entity Framework 4: the example Partner entity is mapped to a database table with it's fields NOT ALLOWED to be NULL (which is ok by design - they're required). Unfortunately, invoking TryUpdateModel when some of the properties are nulls produces ConstraintException which is not expected! I do expect that TryUpdateModel return false in this case. It is ok that EF wouldn't allow set a property value to null if it should not be, but the TryUpdateMethod should handle that, and add the error to ModelState errors collection. I am wrong, or somebody screwed the implementation of TryUpdateModel method?

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  • 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.

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  • 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?

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  • 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!

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  • 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

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  • NHibernate Session Load vs Get when using Table per Hierarchy. Always use ISession.Get&lt;T&gt; for TPH to work.

    - by Rohit Gupta
    Originally posted on: http://geekswithblogs.net/rgupta/archive/2014/06/01/nhibernate-session-load-vs-get-when-using-table-per-hierarchy.aspxNHibernate ISession has two methods on it : Load and Get. Load allows the entity to be loaded lazily, meaning the actual call to the database is made only when properties on the entity being loaded is first accessed. Additionally, if the entity has already been loaded into NHibernate Cache, then the entity is loaded directly from the cache instead of querying the underlying database. ISession.Get<T> instead makes the call to the database, every time it is invoked. With this background, it is obvious that we would prefer ISession.Load<T> over ISession.Get<T> most of the times for performance reasons to avoid making the expensive call to the database. let us consider the impact of using ISession.Load<T> when we are using the Table per Hierarchy implementation of NHibernate. Thus we have base class/ table Animal, there is a derived class named Snake with the Discriminator column being Type which in this case is “Snake”. If we load This Snake entity using the Repository for Animal, we would have a entity loaded, as shown below: public T GetByKey(object key, bool lazy = false) { if (lazy) return CurrentSession.Load<T>(key); return CurrentSession.Get<T>(key); } var tRepo = new NHibernateReadWriteRepository<TPHAnimal>(); var animal = tRepo.GetByKey(new Guid("602DAB56-D1BD-4ECC-B4BB-1C14BF87F47B"), true); var snake = animal as Snake; snake is null As you can see that the animal entity retrieved from the database cannot be cast to Snake even though the entity is actually a snake. The reason being ISession.Load prevents the entity to be cast to Snake and will throw the following exception: System.InvalidCastException :  Message=Unable to cast object of type 'TPHAnimalProxy' to type 'NHibernateChecker.Model.Snake'. Thus we can see that if we lazy load the entity using ISession.Load<TPHAnimal> then we get a TPHAnimalProxy and not a snake. =============================================================== However if do not lazy load the same cast works perfectly fine, this is since we are loading the entity from database and the entity being loaded is not a proxy. Thus the following code does not throw any exceptions, infact the snake variable is not null: var tRepo = new NHibernateReadWriteRepository<TPHAnimal>(); var animal = tRepo.GetByKey(new Guid("602DAB56-D1BD-4ECC-B4BB-1C14BF87F47B"), false); var snake = animal as Snake; if (snake == null) { var snake22 = (Snake) animal; }

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  • 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.

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  • 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).

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  • 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?

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  • 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 ?

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  • 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?)

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