Search Results

Search found 13710 results on 549 pages for 'relational model'.

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 97/549 | < Previous Page | 93 94 95 96 97 98 99 100 101 102 103 104  | Next Page >

  • Passing viewmodel to actionresult creates new viewmodel

    - by Jonas Bohez
    I am using a viewmodel, which i then when to send to an actionresult to use (the modified viewmodel) But in the controller, i lose the list and objects in my viewmodel. This is my view: @using PigeonFancier.Models @model PigeonFancier.Models.InschrijvingModel @using (Html.BeginForm("UpdateInschrijvingen","Melker",Model)) { <div> <fieldset> <table> @foreach (var item in Model.inschrijvingLijst) { <tr> <td>@Html.DisplayFor(model => item.Duif.Naam)</td> <td> @Html.CheckBoxFor(model => item.isGeselecteerd)</td> </tr> } </table> <input type="submit" value="Wijzigen"/> </fieldset> </div> } This is my controller, which does nothing at the moment until i can get the full viewmodel back from the view. public ActionResult UpdateInschrijvingen(InschrijvingModel inschrijvingsModel) { // inschrijvingsModel is not null, but it creates a new model before it comes here with //Use the model for some updates return RedirectToAction("Inschrijven", new { vluchtId = inschrijvingsModel.vlucht.VluchtId }); } This is the model with the List and some other objects who become null because it creates a new model when it comes back from the view to the actionresult public class InschrijvingModel { public Vlucht vlucht; public Duivenmelker duivenmelker; public List<CheckBoxModel> inschrijvingLijst { get; set; } public InschrijvingModel() { // Without this i get, No parameterless constructor defined exception. // So it uses this when it comes back from the view to make a new model } public InschrijvingModel(Duivenmelker m, Vlucht vl) { inschrijvingLijst = new List<CheckBoxModel>(); vlucht = vl; duivenmelker = m; foreach (var i in m.Duiven) { inschrijvingLijst.Add(new CheckBoxModel(){Duif = i, isGeselecteerd = i.IsIngeschrevenOpVlucht(vl)}); } } What is going wrong and how should i fix this problem please? Thanks

    Read the article

  • Calling SubmitChanges on DataContext does not update database.

    - by drasto
    In C# ASP.NET MVC application I use Link to SQL to provide data for my application. I have got simple database schema like this: In my controller class I reference this data context called Model (as you can see on the right side of picture in properties) like this: private Model model = new Model(); I've got a table (List) of Series rendered on my page. It renders properly and I was able to add delete functionality to delete Series like this: public ActionResult Delete(int id) { model.Series.DeleteOnSubmit(model.Series.SingleOrDefault(s => s.ID == id)); model.SubmitChanges(); return RedirectToAction("Index"); } Where appropriate action link looks like this: <%: Html.ActionLink("Delete", "Delete", new { id=item.ID })%> Also create (implemented in similar way) works fine. However edit does not work. My edit looks like this: public ActionResult Edit(int id) { return View(model.Series.SingleOrDefault(s => s.ID == id)); } [HttpPost] public ActionResult Edit(Series series) { if (ModelState.IsValid) { UpdateModel(series); series.Title = series.Title + " some string to ensure title has changed"; model.SubmitChanges(); return RedirectToAction("Index"); } I have controlled that my database has a primary key set up correctly. I debugged my application and found out that everything works as expected until the line with model.SubmitChanges();. This command does not apply the changes of Title property(or any other) against the database. Please help.

    Read the article

  • Does this schema sound better suited for a document-oriented data store or relational?

    - by Blaine LaFreniere
    Disclaimer: let me know if this question is better suited for serverfault.com I want to store information on music, specifically: genres artists albums songs This information will be used in a web application, and I want people to be able to see all of the songs associated to an album, and albums associated to an artist, and artists associated to a genre. I'm currently using MySQL, but before I make a decision to switch I want to know: How easy is scaling horizontally? Is it easier to manage than an SQL based solution? Would the above data I want to store be too hard to do schema-free? When I think association, I immediately think RDBMSs; can data be stored in something like CouchDB but still have some kind of association as stated above?

    Read the article

  • How to programmatically bind to a Core Data model?

    - by Dave Gallagher
    Hello. I have a Core Data model, and was wondering if you know how to create a binding to an Entity, programmatically? Normally you use bind:toObject:withKeyPath:options: to create a binding. But I'm having a little difficulty getting this to work with Core Data, and couldn't find anything in Apple's docs regarding doing this programmatically. The Core Data model is simple: An Entity called Book An Attribute of Book called author (NSString) I have an object called BookController. It looks like so: @interface BookController : NSObject { NSString *anAuthor; } @property (nonatomic, retain) NSString *anAuthor; // @synthesize anAuthor; inside @implementation I'd like to bind anAuthor inside BookController, to author inside a Book entity. This is how I'm attempting to wrongly do it (it partially works): // A custom class I made, providing an interface to the Core Data database CoreData *db = [[CoreData alloc] init]; // Creating a Book entity, saving it [db addMocObject:@"Book"]; [db saveMoc]; // Fetching the Book entity we just created NSArray *books = [db fetchObjectsForEntity:@"Book" withPredicate:nil withSortDescriptors:nil]; NSManagedObject *book = [books objectAtIndex:0]; // Creating the binding BookController *bookController = [[BookController alloc] init]; [bookController bind:@"anAuthor" toObject:book withKeyPath:@"author" options:nil]; // Manipulating the binding [bookController setAnAuthor:@"Bill Gates"]; Now, when updating from the perspective of bookController, things don't work quite right: // Testing the binding from the bookController's perspective [bookController setAnAuthor:@"Bill Gates"]; // Prints: "bookController's anAuthor: Bill Gates" NSLog(@"bookController's anAuthor: %@", [bookController anAuthor]); // OK! // ERROR HERE - Prints: "bookController's anAuthor: (null)" NSLog(@"Book's author: %@", [book valueForKey:@"author"]); // DOES NOT WORK! :( When updating from the perspective of the Book entity, things work fine: // ------------------------------ // Testing the binding from the Book's (Entity) perspective (this works perfect) [book setValue:@"Steve Jobs" forKey:@"author"]; // Prints: "bookController's anAuthor: Steve Jobs" NSLog(@"bookController's anAuthor: %@", [bookController anAuthor]); // OK! // Prints: "bookController's anAuthor: Steve Jobs" NSLog(@"Book's author: %@", [book valueForKey:@"author"]); // OK! It appears that the binding is partially working. I can update it on the side of the Model and it propagates up to the Controller via KVO, but if I update it on the side of the Controller, it doesn't trickle down to the Model via KVC. Any idea on what I'm doing wrong? Thanks so much for looking! :)

    Read the article

  • How can I add dynamic field in the model in django ?

    - by Wu Jie
    Hello, I'm using django to create a application download site. I try to write a model, that the admin can add the different download content dynamically in the admin page. For example I have a software named foobar, it have 3 different version: 1.1, 1.2, 1.3. I would like the user can admin the model by using an add button to add the download link with a download version. But I don't know how to do this in django.

    Read the article

  • How to Set Customer Table with Multiple Phone Numbers? - Relational Database Design

    - by user311509
    CREATE TABLE Phone ( phoneID - PK . . . ); CREATE TABLE PhoneDetail ( phoneDetailID - PK phoneID - FK points to Phone phoneTypeID ... phoneNumber ... . . . ); CREATE TABLE Customer ( customerID - PK firstName phoneID - Unique FK points to Phone . . . ); A customer can have multiple phone numbers e.g. Cell, Work, etc. phoneID in Customer table is unique and points to PhoneID in Phone table. If customer record is deleted, phoneID in Phone table should also be deleted. Do you have any concerns on my design? Is this designed properly? My problem is phoneID in Customer table is a child and if child record is deleted then i can not delete the parent (Phone) record automatically.

    Read the article

  • In MVVM should the ViewModel or Model implement INotifyPropertyChanged?

    - by Edward Tanguay
    Most MVVM examples I have worked through have had the Model implement INotifyPropertyChanged, but in Josh Smith's CommandSink example the ViewModel implements INotifyPropertyChanged. I'm still cognitively putting together the MVVM concepts, so I don't know if: you have to put the INotifyPropertyChanged in the ViewModel to get CommandSink to work this is just an aberration of the norm and it doesn't really matter you should always have the Model implement INotifyPropertyChanged and this is just a mistake which would be corrected if this were developed from a code example to an application What have been others' experiences on MVVM projects you have worked on?

    Read the article

  • What is the best way to archive data in a relational database?

    - by GenericTypeTea
    I have a bit of an issue with a particular aspect of a program I'm working on. I need the ability to archive (fix) a table so that a change anywhere in the system will not affect the results it returns. This is the basic structure of what I need to fix: Recipe --> Recipe (as sub recipe) Recipe --> Ingredients So, if I fix a Recipe, I need to ensure all the sub recipes (including all the sub recipes sub recipes and so forth) are fixed and all its ingredients are fixed. The problem is that the sub recipe and ingredients still need to be modifiable as they are used by other recipes that are not fixed. I came up with a solution whereby I serialize (with protobuf-net) a master object that deals with the recipe and all the sub recipes and ingredients and save the archive data to a table like follows: Archive{ ReferenceId, (i.e. RecipeId) ReferenceTypeId, (i.e. Recipe) ArchiveData varbinary(max) } Now, this works great and is almost perfect... however I totally forgot (I'd love to blame the agile development mentally, however this was just short sighted) that this information needs to be reported on. As far as I'm aware I can't think how I could inflate the serialized data back into my Recipe Object and use it in a Report. I'm using the standard SQL 2005 report services at the moment. Alternatively, I guess I could do the following: Duplicate every table and tag the word "Archive" on the end of the table name. This would then give me an area of specific archive data... but ignoring my simplified example, there'd actually be about 15 tables duplicated. Add a nullable, non-foreign key property called "CopiedFromId" to every table that contains fixed data and duplicate every record that the recipe (and all it's sub recipes and all their sub recipes) touches. Create some sort of denormalised structure that could be restored from at a later date to the original, unfixed recipe. Although I think this would be like option 1 and involve a lot of extra tables. Anyway, I'm at a total loss and do not like any of the ideas particularly. Can anyone please advise the best course of action? EDIT: Or 4) Create tables specific to what the report requires and populate them with the data when the user clicks the report button? This would cause about 4 extra tables for the report in question.

    Read the article

  • Ruby on Rails: Find records based on a method in the model?

    - by sjsc
    I'm looking to use named_scope to find records based on a method in the model. Right now I have in my Order.rb model: def self.paid collect { |order| order if order.paid? } end # the method def paid order.payments.total >= order.total_price end That works, but I can't chain it if I have a shipped named_scope: named_scope :shipped, :conditions => "shipped is true" And I wanted to do: Order.paid.shipped which doesn't work. Any ideas?

    Read the article

  • Microsoft Solver Foundation constraint

    - by emaster70
    Hello, I'm trying to use Microsoft Solver Foundation 2 to solve a fairly complicated situation, however I'm stuck with an UnsupportedModelException even when I dumb down the model as much as possible. Does anyone have an idea of what I'm doing wrong? Following is the least example required to reproduce the problematic behavior. var ctx = SolverContext.GetContext(); var model = ctx.CreateModel(); var someConstant = 1337.0; var decisionA = new Decision(Domain.Real, "decisionA"); var decisionB = new Decision(Domain.Real, "decisionB"); var decisionC = new Decision(Domain.Real, "decisionC"); model.AddConstraint("ca", decisionA <= someConstant); model.AddConstraint("cb", decisionB <= someConstant); model.AddConstraint("cc", decisionC <= someConstant); model.AddConstraint("mainConstraint", Model.Equal(Model.Sum(decisionA, decisionB, decisionC), someConstant)) model.AddGoal("myComplicatedGoal", GoalKind.Minimize, decisionC); var solution = ctx.Solve(); solution.GetReport().WriteTo(Console.Out); Console.ReadKey(); Please consider that my actual model should include, once complete, a few constraints in the form of a*a+b*a <= someValue, so if what I'm willing to do ultimately isn't supported, please let me know in advance. If that's the case I'd also appreciate a suggestion of some other solver with a .NET friendly interface that I could use (only well-known commercial packages, please). Thanks in advance

    Read the article

  • Is it possible to dynamically discover tables in an Entity Framework model ?

    - by Scott Davies
    Hi, I have co-workers working on an Entity Framework model that changes structure (entities), over time as software development progresses. I've written some utilities that interact with the tables within the model, but I'd like to have the code dynamically discover the tables. Is there a way I can do this ? Perhaps with ADO.NET to get the table names and then store them in a collection ? Thanks, Scott

    Read the article

  • What resources will help me understand the fundamentals of Relational Database Systems.

    - by Rachel
    This are few of the fundamental database questions which has always given me trouble. I have tried using google and wiki but I somehow I miss out on understanding the functionality rather than terminology. If possible would really appreciate if someone can share more insights on this questions using some visual representative examples. What is a key? A candidate key? A primary key? An alternate key? A foreign key? What is an index and how does it help your database? What are the data types available and when to use which ones?

    Read the article

  • CakePHP: Can I ignore a field when reading the Model from the DB?

    - by Daniel Magliola
    In one of my models, I have a "LONGTEXT" field that has a big dump of a bunch of stuff that I never care to read, and it slows things down, since I'm moving much more data between the DB and the web app. Is there a way to specify in the model that I want CakePHP to simply ignore that field, and never read it or do anything with it? I really want to avoid the hassle of creating a separate table and a separate model, only for this field. Thanks! Daniel

    Read the article

  • Jena Effects of Different Entailment Regimes

    - by blueomega
    I am trying sparql and the use of entailment. As a example i used http://www.w3.org/TR/2010/WD-sparql11-entailment-20100126/#t112 i try to put them in jena. OntClass book1= model.createClass(NS+"book1"); OntClass book2=model.createClass(NS+"book2"); OntClass book3=model.createClass(NS+"book3"); OntClass publication=model.createClass(NS+"publication"); OntClass article=model.createClass(NS+"article"); OntClass mit=model.createClass(NS+"MIT"); ObjectProperty a = model.createObjectProperty(NS+"a"); ObjectProperty publishes = model.createObjectProperty(NS+"publishes"); book1.addProperty(a, publication); book2.addProperty(a, article); publication.addSubClass(article); publishes.addRange(publication); mit.addProperty(publishes, book3); where model is type OntModel. and i used the query similar to the problem "PREFIX table: "I have correct namespace here"+ "SELECT *"+ "WHERE"+ "{"+ " ?x ?y table:publication ."+ "}"; The model was created like this. Hope OntModelSpec is ok. OntModel m = ModelFactory.createOntologyModel(OntModelSpec.OWL_MEM_RDFS_INF, null); i get as results from query x y | http://www.example.com/ontologies/sample.owl#publishes | rdfs:range | | http://www.example.com/ontologies/sample.owl#article | rdfs:subClassOf | | http://www.example.com/ontologies/sample.owl#book1 | http://www.example.com/ontologies/sample.owl#a | | http://www.example.com/ontologies/sample.owl#publication | rdfs:subClassOf | | http://www.example.com/ontologies/sample.owl#book3 | rdf:type | Can anyone give me a example, with and without entailment, so a cant try code, can get the results right.

    Read the article

  • Crashes in Core Data's Inferred Mapping Model Creation (Lightweight Migration). Threading Issue?

    - by enchilada
    I'm getting random crashes when creating an inferred mapping model (with Core Data's lightweight migration) within my application. By the way, I have to do it programmatically in my application while it is running. This is how I create this model (after I have made proper currentModel and newModel objects, of course): NSMappingModel *mappingModel = [NSMappingModel inferredMappingModelForSourceModel:currentModel destinationModel:newModel error:&error]; The problem is this: This method is crashing randomly. When it works, it works just fine without issues. But when it crashes, it crashes my application (instead of returning nil to signify that the method failed, as it should). By randomly, I mean that sometimes it happens and sometimes not. It is unpredictable. Now, here is the deal: I'm running this method in another thread. More precisely, it is located inside a block that is passed via GCD to run on the global main queue. I need to do this for my UI to appear crisp to the user, i.e. so that I can display a progress indicator while the work is underway. The strange thing seems to be that if I remove the GCD stuff and just let it run on the main thread, it seems to be working fine and never crashing. Thus, could it be because I'm running this on a different thread that this is crashing? I somehow find that weird because I don't believe I'm breaking any Core Data rules regarding multi-threading. In particular, I'm not passing any managed objects around, and whenever I need access to the MOC, I create a new MOC, i.e. I'm not relying on any MOC (or for that matter: anything) that has been created earlier on the main thread. Besides the little MOC stuff that occurs, occurs after the mapping model creation method, i.e. after the point at which the app crashes, so it can't possibly be a cause of the crashes under consideration here. All I'm doing is taking two MOMs and asking for a mapping model between them. That can't be wrong even under threading, now can it? Any ideas on what could be going on?

    Read the article

  • Django admin breaking with non-default primary_key for model with a m2m relationship ?

    - by Gj
    I have a simple Post model with a m2m field to a Tag model. The Tag had for some reason to use a non default primary key. Inside the admin page for a Post, the labels for the multiple selection field for Tags appear, but not the input field itself. I also tried using the filter_horizontal for the tags, but still only the labels appear without the actual field. Any ideas why it breaks and/or workarounds? Thanks!

    Read the article

  • Is it safe to put reference to current user in User model in Rails?

    - by Art Shayderov
    You know, I think I have to check current user in the model callbacks (like before_update). Rather than rely solely on adding where ('something.user_id = ?', 'current_user.id') in the controllers. I need something like Thread.CurrentPrincipal in .NET Is it safe to put reference to current user in User model? I'm sorry I don't really understand how it works under the hood yet. Or how you do it The Rails way? Sorry if this a silly question.

    Read the article

  • Qt – How to add calculated column in QsqlRelationalTableModel ?

    - by user289175
    I have an table view showed part description, quantity, price And I have a Model/View using this code model = new QSqlRelationalTableModel(this); model->setTable("parts"); model->setRelation(3,QSqlRelation("part_tbl","part_id","part_desc")); model->select(); ui->tableView->setModel(model); I need to add a new column that shows quantity * price in the table view. It's important to know I'm using QsqlRelationalTableModel Help is appreciated, Thanks in advance

    Read the article

  • What are the Options for Storing Hierarchical Data in a Relational Database?

    - by orangepips
    Good Overviews One more Nested Intervals vs. Adjacency List comparison: the best comparison of Adjacency List, Materialized Path, Nested Set and Nested Interval I've found. Models for hierarchical data: slides with good explanations of tradeoffs and example usage Representing hierarchies in MySQL: very good overview of Nested Set in particular Hierarchical data in RDBMSs: most comprehensive and well organized set of links I've seen, but not much in the way on explanation Options Ones I am aware of and general features: Adjacency List: Columns: ID, ParentID Easy to implement. Cheap node moves, inserts, and deletes. Expensive to find level (can store as a computed column), ancestry & descendants (Bridge Hierarchy combined with level column can solve), path (Lineage Column can solve). Use Common Table Expressions in those databases that support them to traverse. Nested Set (a.k.a Modified Preorder Tree Traversal) First described by Joe Celko - covered in depth in his book Trees and Hierarchies in SQL for Smarties Columns: Left, Right Cheap level, ancestry, descendants Compared to Adjacency List, moves, inserts, deletes more expensive. Requires a specific sort order (e.g. created). So sorting all descendants in a different order requires additional work. Nested Intervals Combination of Nested Sets and Materialized Path where left/right columns are floating point decimals instead of integers and encode the path information. Bridge Table (a.k.a. Closure Table: some good ideas about how to use triggers for maintaining this approach) Columns: ancestor, descendant Stands apart from table it describes. Can include some nodes in more than one hierarchy. Cheap ancestry and descendants (albeit not in what order) For complete knowledge of a hierarchy needs to be combined with another option. Flat Table A modification of the Adjacency List that adds a Level and Rank (e.g. ordering) column to each record. Expensive move and delete Cheap ancestry and descendants Good Use: threaded discussion - forums / blog comments Lineage Column (a.k.a. Materialized Path, Path Enumeration) Column: lineage (e.g. /parent/child/grandchild/etc...) Limit to how deep the hierarchy can be. Descendants cheap (e.g. LEFT(lineage, #) = '/enumerated/path') Ancestry tricky (database specific queries) Database Specific Notes MySQL Use session variables for Adjacency List Oracle Use CONNECT BY to traverse Adjacency Lists PostgreSQL ltree datatype for Materialized Path SQL Server General summary 2008 offers HierarchyId data type appears to help with Lineage Column approach and expand the depth that can be represented.

    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 | 93 94 95 96 97 98 99 100 101 102 103 104  | Next Page >