Search Results

Search found 8349 results on 334 pages for 'entity groups'.

Page 29/334 | < Previous Page | 25 26 27 28 29 30 31 32 33 34 35 36  | Next Page >

  • Entity framework 4 many-to-many insertion?

    - by Saxman
    Hi all, I'm not very familiar with the many-to-many insertion process using Entity Framework 4, POCO. I have a blog with 3 tables: Post, Comment, and Tag. A Post can have many Tags and a Tag can be in many Posts. Here are the Post and Tag models: public class Tag { public int Id { get; set; } [Required] [StringLength(25, ErrorMessage = "Tag name can't exceed 25 characters.")] public string Name { get; set; } public virtual ICollection<Post> Posts { get; set; } } public class Post { public int Id { get; set; } [Required] [StringLength(512, ErrorMessage = "Title can't exceed 512 characters")] public string Title { get; set; } [Required] [AllowHtml] public string Content { get; set; } public string FriendlyUrl { get; set; } public DateTime PostedDate { get; set; } public bool IsActive { get; set; } public virtual ICollection<Comment> Comments { get; set; } public virtual ICollection<Tag> Tags { get; set; } } Now when I'm adding a new post, I'm not sure what would be the right way to do. I'm thinking that I'll have a textbox where I can select multiple tags for that post (this part is already done), in my controller, I will check to see if the tag is already exists or not, if not, then I will insert the new tag. But I'm not even sure based on the models that I've created for EF, will they create a PostsTags table, or they are creating just a Tags and a Posts table and links between the two? How would I insert the new Post and set the tags to that post? Is it just newPost.Tags = Tags (where Tags are the one that got selected, do I even need to check to see if they already exists?), and then something like _post.Add(newPost);? Thanks.

    Read the article

  • Entity Framework: An object with the same key already exists in the objectstatemanager

    - by NealR
    I see that this question has been asked a lot, however I haven't found anything yet that solves the problem I'm having. Obviously i'm using the Entity Framework to perform an update to a record. Once the updates are complete, however, whenever I try to save I get the following error message: An object with the same key already exists in the objectstatemanager At first I was passing in a collection object from the view that contained a copy of the the ZipCodeTerritory model object zipToUpdate. I changed the code by pulling this object out and just sending in the relevant fields instead. However, I'm still getting the same error. What's also weird is the first time I run this code, it works fine. Any attempt after that I get the error. Controller Here is the code from the method calling the edit function public static string DescriptionOnly(ZipCodeIndex updateZip) { if (!string.IsNullOrWhiteSpace(updateZip.newEffectiveDate) || !string.IsNullOrWhiteSpace(updateZip.newEndDate)) { return "Neither effective or end date can be present if updating Territory Code only; "; } _updated = 0; foreach (var zipCode in updateZip.displayForPaging.Where(x => x.Update)) { ProcessAllChanges(zipCode, updateZip.newTerritory, updateZip.newStateCode, updateZip.newDescription, updateZip.newChannelCode); } _msg += _updated + " record(s) updated; "; return _msg; } And here is the method that actually does the updating. private static void ProcessAllChanges(ZipCodeTerritory zipToUpdate, string newTerritory, string newStateCode, string newDescription, string newChannelCode) { try { if (!string.IsNullOrWhiteSpace(newTerritory)) zipToUpdate.IndDistrnId = newTerritory; if (!string.IsNullOrWhiteSpace(newStateCode)) zipToUpdate.StateCode = newStateCode; if (!string.IsNullOrWhiteSpace(newDescription)) zipToUpdate.DrmTerrDesc = newDescription; if (!string.IsNullOrWhiteSpace(newChannelCode)) zipToUpdate.ChannelCode = newChannelCode; if (zipToUpdate.EndDate == DateTime.MinValue) zipToUpdate.EndDate = DateTime.MaxValue; _db.Entry(zipToUpdate).State = EntityState.Modified; _db.SaveChanges(); _updated++; } catch (DbEntityValidationException dbEx) { _msg += "Error during update; "; EventLog.WriteEntry("Monet", "Error during ProcessAllChanges: " + zipToUpdate.ToString() + " |EX| " + dbEx.Message); } catch (Exception ex) { _msg += "Error during update; "; EventLog.WriteEntry("Monet", "Error during ProcessAllChanges: " + zipToUpdate.ToString() + " |MESSAGE| " + ex.Message); } } EDIT The ZipCodeIndex object contains a list of ZipCodeTerritory model objects. These aren't being pulled from a linq query, but instead simply passed back to the controller from the view. Here is the signature of the controller method that starts the process: [HttpPost] public ActionResult Update(ZipCodeIndex updateZip, string button)

    Read the article

  • T-4 Templates for ASP.NET Web Form Databound Control Friendly Logical Layers

    - by joycsharp
    I just released an open source project at codeplex, which includes a set of T-4 templates to enable you to build logical layers (i.e. DAL/BLL) with just few clicks! The logical layers implemented here are  based on Entity Framework 4.0, ASP.NET Web Form Data Bound control friendly and fully unit testable. In this open source project you will get Entity Framework 4.0 based T-4 templates for following types of logical layers: Data Access Layer: Entity Framework 4.0 provides excellent ORM data access layer. It also includes support for T-4 templates, as built-in code generation strategy in Visual Studio 2010, where we can customize default structure of data access layer based on Entity Framework. default structure of data access layer has been enhanced to get support for mock testing in Entity Framework 4.0 object model. Business Logic Layer: ASP.NET web form based data bound control friendly business logic layer, which will enable you few clicks to build data bound web applications on top of ASP.NET Web Form and Entity Framework 4.0 quickly with great support of mock testing. Download it to make your web development productive. Enjoy!

    Read the article

  • Getting code-first Entity Framework to build tables on SQL Azure

    - by NER1808
    I am new the code-first Entity Framework. I have tried a few things now, but can't get EF to construct any tables in the my SQL Azure database. Can anyone advise of some steps and settings I should check. The membership provider has no problems create it's tables. I have added the PersistSecurityInfo=True in the connection string. The connection string is using the main user account for the server. When I implement the tables in the database using sql everything works fine. I have the following in the WebRole.cs //Initialize the database Database.SetInitializer<ReykerSCPContext>(new DbInitializer()); My DbInitializer (which does not get run before I get a "Invalid object name 'dbo.ClientAccountIFAs'." when I try to access the table for the first time. Sometime after startup. public class DbInitializer:DropCreateDatabaseIfModelChanges<ReykerSCPContext> { protected override void Seed(ReykerSCPContext context) { using (context) { //Add Doc Types context.DocTypes.Add(new DocType() { DocTypeId = 1, Description = "Statement" }); context.DocTypes.Add(new DocType() { DocTypeId = 2, Description = "Contract note" }); context.DocTypes.Add(new DocType() { DocTypeId = 3, Description = "Notification" }); context.DocTypes.Add(new DocType() { DocTypeId = 4, Description = "Invoice" }); context.DocTypes.Add(new DocType() { DocTypeId = 5, Description = "Document" }); context.DocTypes.Add(new DocType() { DocTypeId = 6, Description = "Newsletter" }); context.DocTypes.Add(new DocType() { DocTypeId = 7, Description = "Terms and Conditions" }); //Add ReykerAccounttypes context.ReykerAccountTypes.Add(new ReykerAccountType() { ReykerAccountTypeID = 1, Description = "ISA" }); context.ReykerAccountTypes.Add(new ReykerAccountType() { ReykerAccountTypeID = 2, Description = "Trading" }); context.ReykerAccountTypes.Add(new ReykerAccountType() { ReykerAccountTypeID = 3, Description = "SIPP" }); context.ReykerAccountTypes.Add(new ReykerAccountType() { ReykerAccountTypeID = 4, Description = "CTF" }); context.ReykerAccountTypes.Add(new ReykerAccountType() { ReykerAccountTypeID = 5, Description = "JISA" }); context.ReykerAccountTypes.Add(new ReykerAccountType() { ReykerAccountTypeID = 6, Description = "Direct" }); context.ReykerAccountTypes.Add(new ReykerAccountType() { ReykerAccountTypeID = 7, Description = "ISA & Direct" }); //Save the changes context.SaveChanges(); } and my DBContext class looks like public class ReykerSCPContext : DbContext { //set the connection explicitly public ReykerSCPContext():base("ReykerSCPContext"){} //define tables public DbSet<ClientAccountIFA> ClientAccountIFAs { get; set; } public DbSet<Document> Documents { get; set; } public DbSet<DocType> DocTypes { get; set; } public DbSet<ReykerAccountType> ReykerAccountTypes { get; set; } protected override void OnModelCreating(DbModelBuilder modelBuilder) { //Runs when creating the model. Can use to define special relationships, such as many-to-many. } The code used to access the is public List<ClientAccountIFA> GetAllClientAccountIFAs() { using (DataContext) { var caiCollection = from c in DataContext.ClientAccountIFAs select c; return caiCollection.ToList(); } } and it errors on the last line. Help!

    Read the article

  • How to authenticate users in nested groups in Apache LDAP?

    - by mark
    I've working LDAP authentication with the following setup AuthName "whatever" AuthType Basic AuthBasicProvider ldap AuthLDAPUrl "ldap://server/OU=SBSUsers,OU=Users,OU=MyBusiness,DC=company,DC=local?sAMAccountName?sub?(objectClass=*)" Require ldap-group CN=MySpecificGroup,OU=Security Groups,OU=MyBusiness,DC=company,DC=local This works, however I've to put all users I want to authenticate into MySpecificGroup. But on LDAP server I've configured that MySpecificGroup also contains the group MyOtherGroup with another list of users. But those users in MyOtherGroup are not authenticated, I've to manually add them all to MySpecificGroup and basically can't use the nested grouping. I'm using Windows SBS 2003. Is there a way to configure Apache LDAP to do this? Or is there a problem with possible infinite recursion and thus not allowed?

    Read the article

  • Correct way to edit and update complex viewmodel objects using asp.net-mvc2 and entity framework

    - by jslatts
    I have a table in my database with a one to many relationship to another table: ParentObject ID Name Description ChildObject ID Name Description ParentObjectID AnotherObjectID The objects are mapped into Entity Framework and exposed through a data access class. It seemed like ViewModels are recommended when the data to be displayed greatly differs from the domain object, so I created a ViewModel as follows: public class ViewModel { public IList<ParentObject> ParentObjects { get; set; } public ParentObject selectedObject { get; set; } public IList<ChildObject> ChildObjects { get; set; } } I have a view that displays a list of ParentObjects and when clicked will allow a ChildObject to be modified saved. <% using (Html.BeginForm()) { %> <table> <% foreach (var parent in Model.ParentObjects) { %> <tr> <td> ObjectID [<%= Html.Encode(parent.ID)%>] </td> <td> <%= Html.Encode(parent.Name)%> </td> <td> <%= Html.Encode(parent.Description)%> </td> </tr> <% } %> </table> <% if (Model.ParentObject != null) { %> <div> Name:<br /> <%= Html.TextBoxFor(model => model.ParentObject.Name) %> <%= Html.ValidationMessageFor(model => model.ParentObject.Name, "*")%> </div> <div> Description:<br /> <%= Html.TextBoxFor(model => model.ParentObject.Description) %> <%= Html.ValidationMessageFor(model => model.ParentObject.Description, "*")%> </div> <div> Child Objects </div> <% for (int i = 0; i < Model.ParentObject.ChildObjects.Count(); i++) { %> <div> <%= Html.DisplayTextFor(sd => sd.ChildObjects[i].Name) %> </div> <div> <%= Html.HiddenFor(sd => sd.ChildObjects[i].ID )%> <%= Html.TextBoxFor( sd => sd.ChildObjects[i].Description) %> <%= Html.ValidationMessageFor(sd => sd.ChildObjects[i].Description, "*") %> </div> <% } } } %> This all works fine. My question is around the best way to update the EF objects and persist the changes back to the database. I initially tried: [HttpPost] public ActionResult Edit(ViewModel viewModel) { ParentObject parent = myRepository.GetParentObjectByID(viewModel.SelectedObject.ID); if ((!ModelState.IsValid) || !TryUpdateModel(parent, "SelectedObject", new[] { "Name", "Description" })) { || !TryUpdateModel(parent.ChildObjects, "ChildObjects", new[] { "Name", "Description" })) { //Code to handle failure and return the current model snipped return View(viewModel); } myRepository.Save(); return RedirectToAction("Edit"); } When I try to save a change to the child object, I get this exception: Entities in 'MyEntities.ChildObject' participate in the 'FK_ChildObject_AnotherObject' relationship. 0 related 'AnotherObject' were found. 1 'AnotherObject' is expected. Investigation on StackOverflow and generally googling led me to this blog post that seems to describe my problem: TryUpdateModel() does not correctly handle nested collections. Apparently, (and stepping through the debugger confirms this) it creates a new ChildObject instead of associating with the EF objects from my instantiated context. My hacky work around is this: if (viewModel.ChildObjects.Count > 0) { foreach (ChildObject modelChildObject in viewModel.ChildObjects) { ChildObject childToUpdate = ParentObject.ChildObject.Where(a => a.ID == modelChildObject.ID).First(); childToUpdate.Name = modelChildObject.Name; } } This seems to work fine. My question to you good folks: Is there correct way to do this? I tried following the suggestion for making a custom model binder per the blog link I posted above but it didn't work (there was an issue with reflection) and I needed to get something going ASAP. PS - I tried to cleanup the code to hide specific information, so beware I may have hosed something up. I mainly just want to know if other people have solved this problem. Thanks!

    Read the article

  • Dynamic Data - Make Friendly Column Names?

    - by davemackey
    I've created a Dynamic Data project with an Entity Framework model. It works nicely. But, right now it shows all my database tables with the db column names - which aren't always the most friendly (e.g. address_line_1). How can I got about giving these more friendly column titles that will display to the end user?

    Read the article

  • MVC 2 Entity Framework View Model Insert

    - by cannibalcorpse
    This is driving me crazy. Hopefully my question makes sense... I'm using MVC 2 and Entity Framework 1 and am trying to insert a new record with two navigation properties. I have a SQL table, Categories, that has a lookup table CategoryTypes and another self-referencing lookup CategoryParent. EF makes two nav properties on my Category model, one called Parent and another called CategoryType, both instances of their respective models. On my view that creates the new Category, I have two dropdowns, one for the CategoryType and another for the ParentCategory. When I try and insert the new Category WITHOUT the ParentCategory, which allows nulls, everything is fine. As soon as I add the ParentCategory, the insert fails, and oddly (or so I think) complains about the CategoryType in the form of this error: 0 related 'CategoryTypes' were found. 1 'CategoryTypes' is expected. When I step through, I can verifiy that both ID properties coming in on the action method parameter are correct. I can also verify that when I go to the db to get the CategoryType and ParentCategory with the ID's, the records are being pulled fine. Yet it fails on SaveChanges(). All that I can see is that my CategoryParent dropdownlistfor in my view, is somehow causing the insert to bomb. Please see my comments in my httpPost Create action method. My view model looks like this: public class EditModel { public Category MainCategory { get; set; } public IEnumerable<CategoryType> CategoryTypesList { get; set; } public IEnumerable<Category> ParentCategoriesList { get; set; } } My Create action methods look like this: // GET: /Categories/Create public ActionResult Create() { return View(new EditModel() { CategoryTypesList = _db.CategoryTypeSet.ToList(), ParentCategoriesList = _db.CategorySet.ToList() }); } // POST: /Categories/Create [HttpPost] public ActionResult Create(Category mainCategory) { if (!ModelState.IsValid) return View(new EditModel() { MainCategory = mainCategory, CategoryTypesList = _db.CategoryTypeSet.ToList(), ParentCategoriesList = _db.CategorySet.ToList() }); mainCategory.CategoryType = _db.CategoryTypeSet.First(ct => ct.Id == mainCategory.CategoryType.Id); // This db call DOES get the correct Category, but fails on _db.SaveChanges(). // Oddly the error is related to CategoryTypes and not Category. // Entities in 'DbEntities.CategorySet' participate in the 'FK_Categories_CategoryTypes' relationship. // 0 related 'CategoryTypes' were found. 1 'CategoryTypes' is expected. //mainCategory.Parent = _db.CategorySet.First(c => c.Id == mainCategory.Parent.Id); // If I just use the literal ID of the same Category, // AND comment out the CategoryParent dropdownlistfor in the view, all is fine. mainCategory.Parent = _db.CategorySet.First(c => c.Id == 2); _db.AddToCategorySet(mainCategory); _db.SaveChanges(); return RedirectToAction("Index"); } Here is my Create form on the view : <% using (Html.BeginForm()) {%> <%= Html.ValidationSummary(true) %> <fieldset> <legend>Fields</legend> <div> <%= Html.LabelFor(model => model.MainCategory.Parent.Id) %> <%= Html.DropDownListFor(model => model.MainCategory.Parent.Id, new SelectList(Model.ParentCategoriesList, "Id", "Name")) %> <%= Html.ValidationMessageFor(model => model.MainCategory.Parent.Id) %> </div> <div> <%= Html.LabelFor(model => model.MainCategory.CategoryType.Id) %> <%= Html.DropDownListFor(model => model.MainCategory.CategoryType.Id, new SelectList(Model.CategoryTypesList, "Id", "Name"))%> <%= Html.ValidationMessageFor(model => model.MainCategory.CategoryType.Id)%> </div> <div> <%= Html.LabelFor(model => model.MainCategory.Name) %> <%= Html.TextBoxFor(model => model.MainCategory.Name)%> <%= Html.ValidationMessageFor(model => model.MainCategory.Name)%> </div> <div> <%= Html.LabelFor(model => model.MainCategory.Description)%> <%= Html.TextAreaFor(model => model.MainCategory.Description)%> <%= Html.ValidationMessageFor(model => model.MainCategory.Description)%> </div> <div> <%= Html.LabelFor(model => model.MainCategory.SeoName)%> <%= Html.TextBoxFor(model => model.MainCategory.SeoName, new { @class = "large" })%> <%= Html.ValidationMessageFor(model => model.MainCategory.SeoName)%> </div> <div> <%= Html.LabelFor(model => model.MainCategory.HasHomepage)%> <%= Html.CheckBoxFor(model => model.MainCategory.HasHomepage)%> <%= Html.ValidationMessageFor(model => model.MainCategory.HasHomepage)%> </div> <p><input type="submit" value="Create" /></p> </fieldset> <% } %> Maybe I've just been staying up too late playing with MVC 2? :) Please let me know if I'm not being clear enough.

    Read the article

  • GUID or int entity key with SQL Compact/EF4?

    - by David Veeneman
    This is a follow-up to an earlier question I posted on EF4 entity keys with SQL Compact. SQL Compact doesn't allow server-generated identity keys, so I am left with creating my own keys as objects are added to the ObjectContext. My first choice would be an integer key, and the previous answer linked to a blog post that shows an extension method that uses the Max operator with a selector expression to find the next available key: public static TResult NextId<TSource, TResult>(this ObjectSet<TSource> table, Expression<Func<TSource, TResult>> selector) where TSource : class { TResult lastId = table.Any() ? table.Max(selector) : default(TResult); if (lastId is int) { lastId = (TResult)(object)(((int)(object)lastId) + 1); } return lastId; } Here's my take on the extension method: It will work fine if the ObjectContext that I am working with has an unfiltered entity set. In that case, the ObjectContext will contain all rows from the data table, and I will get an accurate result. But if the entity set is the result of a query filter, the method will return the last entity key in the filtered entity set, which will not necessarily be the last key in the data table. So I think the extension method won't really work. At this point, the obvious solution seems to be to simply use a GUID as the entity key. That way, I only need to call Guid.NewGuid() method to set the ID property before I add a new entity to my ObjectContext. Here is my question: Is there a simple way of getting the last primary key in the data store from EF4 (without having to create a second ObjectContext for that purpose)? Any other reason not to take the easy way out and simply use a GUID? Thanks for your help.

    Read the article

  • Windows and SQL Azure Best Practices: Affinity Groups

    - by BuckWoody
    When you create a Windows Azure application, you’ll pick a subscription to put it under. This is a billing container - underneath that, you’ll deploy a Hosted Service. That holds the Web and Worker Roles that you’ll deploy for your applications. along side that, you use the Storage Account to create storage for the application. (In some cases, you might choose to use only storage or Roles - the info here applies anyway) As you are setting up your environment, you’re asked to pick a “region” where your application will run. If you choose a Region, you’ll be asked where to put the Roles. You’re given choices like Asia, North America and so on. This is where the hardware that physically runs your code lives. We have lots of fault domains, power considerations and so on to keep that set of datacenters running, but keep in mind that this is where the application lives. You also get this selection for Storage Accounts. When you make new storage, it’s a best practice to put it where your computing is. This makes the shortest path from the code to the data, and then back out to the user. One of the selections for the location is “Anywhere U.S.”. This selection might be interpreted to mean that we will bias towards keeping the data and the code together, but that may not be the case. There is a specific abstraction we created for just that purpose: Affinity Groups. An Affinity Group is simply a name you can use to tie together resources. You can do this in two places - when you’re creating the Hosted Service (shown above) and on it’s own tree item on the left, called “Affinity Groups”. When you select either of those actions, You’re presented with a dialog box that allows you to specify a name, and then the Region that  names ties the resources to. Now you can select that Affinity Group just as if it were a Region, and your code and data will stay together. That helps with keeping the performance high. Official Documentation: http://msdn.microsoft.com/en-us/library/windowsazure/hh531560.aspx

    Read the article

  • SQLAuthority News – Reliving TechEd with Vinod Kumar at Bangalore User Groups

    - by pinaldave
    TechEd India 2012 was held in Bangalore last March 21 to 23, 2012. Just like every year, this event is bigger, grander and inspiring. Here is my blog post reviewing the event SQLAuthority News – #TechEdIn – TechEd India 2012 Memories and Photos. For me this is family event – I get to meet my friends who are dear as my family. I like to call User Groups as family too. Family shares life’s personal happiness and experience – the same way User Group shares professional experiences and quite often UG members become just like family member. When I learned that follower user group together building up a unique event I was pretty excited to learn who is going to be speaker for the event. BDotNet.in – Bangalore .NET Usergroup BITPro.in – Bangalore ITPro Usergroup It was indeed joy when I learned that presenter will be Vinod Kumar, who is integral part of user groups and hardcore SQL Server enthusiast. Vinod Kumar is going to present on following two sessions which are both focused on internals of the Windows and SQL Server. Understanding Windows with SysInternals Tools – This session will cover various tools from usage of Memory, x86 architecture, x64, WOW mode, Page faults, Virtual Memory mapping, OOM scenario, Perf Tool, PAL tool, Logman and more. Peeling the Onion: SQL Server Internals Demystified – This session will cover advanced disk formats, SQL Server 2012 security changes, memory changes, indirect checkPoint and more. I am very excited as this time I will get opportunity to sit in front rows (as I will be reaching there to get best possible position) and learn. I am looking forward to the event and I hope you will join us as well. Event Details: Date: Saturday, April 7, 2012 (10:30am until 1:30pm) Venue: Microsoft, Domlur, Bangalore. Event Details: https://www.facebook.com/events/139444029517882/ This session is FREE for all and everybody and anybody can walk in. Community Blog Posts Here are few of the blog post written by the community on this subject. Vinod Kumar on Reliving #TechEdIn at Blr UG Manas Dash on Reliving TechEd India 2012 with Vinod Kumar Sudeepta Ganguly on SysInternals n SQLInternals with Vinod Kumar Lohith Re Live TechEd India 2012 with Vinod Kumar  Reference: Pinal Dave (http://blog.sqlauthority.com) http://www.youtube.com/watch?v=oRw-p4mahLU Filed under: PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, SQLAuthority Author Visit, T SQL, Technology, Video

    Read the article

  • Preventing Users/Groups from accessing certain Domains

    - by ncphillips
    I have created a Study account which I use when doing anything school related work. It's purpose is to remove the distractions of my normal account, such as social media and news websites. I know /etc/hosts can be edited to block certain domains from being accessed, but this is for all Users, and I don't want to have to switch in and out of Admin to change it every time I want to focus. Is there any way to block these domains for specific Users or Groups?

    Read the article

  • simple sql group by custom groups question [migrated]

    - by alex
    imagine a mysql table that only has 2 columns, an id and a name of a color. with this query I know how many id's do I have for each color. SELECT color_name, count(id) FROM color_table GROUP BY (color_name); red:10 blue:5 yellow:3 green:1 my question is, is there a way I can specify to the "group by" some custom groups?? i mean, is there a query that results in this??: red:10 colors different than red: 9

    Read the article

  • AlwaysOn Availability Groups in SQL Server 2012

    This article discusses and demonstrates AlwaysOn Availability groups in SQL Server 2012, a new feature for high availability. Keep your database and application development in syncSQL Connect is a Visual Studio add-in that brings your databases into your solution. It then makes it easy to keep your database in sync, and commit to your existing source control system. Find out more.

    Read the article

  • Can I remove the systems from a component entity system?

    - by nathan
    After reading a lot about entity/component based engines. I feel like there is no real definition for this kind of engine. Reading this thread: Implementing features in an Entity System and the linked article made me think a lot. I did not feel that comfortable using System concept so I'll write something else, inspired by this pattern. I'd like to know if you think it's a good way to organize game code and what improvements can be made. Regarding a more strict implementation of entity/component based engine, is my solution viable? Do I risk getting stuck at any point due to the lack of flexibility of this implementation (or anything else)? My engine, as for entity/component patterns has entities and components, no systems since the game logic is handled by components. Also, I think the main difference is the fact that my engine will use inherence and OOP concepts in general, I mean, I don't try to minimize them. Entity: an entity is an abstract class. It holds his position, width and height, scale and a list of linked components. The current implementation can be found here (java). Every frame, the entity will be updated (i.e all the components linked to this entity will be updated), and rendered, if a render component is specified. Component: like for entity, a component is an abstract class that must be extended to create new components. The behavior of an entity is created through his components collection. The component implementation can be found here. Components are updated when the owning entity is updated or for only one specific component (render component), rendered. Here is an example of a logic component (i.e not a renderable component, a component that's updated each frame) in charge of listening for keyboard events and a render component in charge of display a plain sprite (i.e not animated).

    Read the article

  • Argument exception after trying to use TryGetObjectByKey

    - by Rickjaah
    Hi, I'm trying to retrieve an object from my database using entity (framework 4) When I use the following code it gives an ArgumentException: An item with the same key has already been added. if (databaseContext.TryGetObjectByKey(entityKey, out result)) { return (result != null && result is TEntityObject) ? result as TEntityObject : null; } else { return null; } When I check the objectContext, I see the entities, but only if I enumerate the specific list of entities manually using VS2010, it works. What am I missing? Do I have to do something else before i can get the item from the database? I have lazy loading set to true. I searched google, but could not find any results, the same for the msdn library

    Read the article

  • Need help understanding Generics, How To Abstract Types Question.

    - by kmacmahon
    I could use some really good links that explain Generics and how to use them. But I also have a very specific question, relater to working on a current project. Given this class constructor: public class SecuredDomainViewModel<TDomainContext, TEntity> : DomainViewModel<TDomainContext, TEntity> where TDomainContext : DomainContext, new() where TEntity : Entity, new() public SecuredDomainViewModel(TDomainContext domainContext, ProtectedItem protectedItem) : base(domainContext) { this.protectedItem = protectedItem; } And its creation this way: DomainViewModel d; d = new SecuredDomainViewModel<MyContext, MyEntityType>(this.context, selectedProtectedItem); Assuming I have 20 different EntityTypes within MyContext, is there any easier way to call the constructor without a large switch statement? Also, since d is DomainViewModel and I later need to access methods from SecuredDomainViewModel, it seems I need to do this: if (((SecuredDomainViewModel<MyContext, MyEntityType>)d).CanEditEntity) But again "MyEntityType" could actually be one of 20 diffent types. Is there anyway to write these types of statements where MyEntityType is returned from some sort of Reflection?

    Read the article

  • Need help understanding Generics, How To Abstract Types Question.

    - by kmacmahon
    I could use some really good links that explain Generics and how to use them. But I also have a very specific question, relater to working on a current project. Given this class constructor: public class SecuredDomainViewModel<TDomainContext, TEntity> : DomainViewModel<TDomainContext, TEntity> where TDomainContext : DomainContext, new() where TEntity : Entity, new() And its creation this way: DomainViewModel d; d = new SecuredDomainViewModel<MyContext, MyEntityType>(this.context, selectedProtectedItem); Assuming I have 20 EntityTypes within MyContext, is there any easier way to call the constructor without a large switch statement? Also, since d is DomainViewModel and I want to access methods for SecuredDomainViewModel, it seems I need to do this: if (((SecuredDomainViewModel<MyContext, MyEntityType>)d).IsBusy) But again "MyEntityType" could actually be one of 20 types. Is there anyway to write these types of statements where MyEntityType is returned from some sort of Reflection?

    Read the article

  • Instantiating a context in LINQ to Entities

    - by Jagd
    I've seen two different manners that programmers approach when creating an entity context in their code. The first is like such, and you can find it all over the MSDN code examples: public void DoSomething() { using TaxableEducationEntities context = new TaxableEducationEntities()) { // business logic and whatever else } } The second is to create the context as a private attribute in some class that encapsulates your business logic. So you would have something like: public class Education_LINQ { private TaxableEducationEntities context = new TaxableEducationEntities(); public void DoSomething() { var result = from a in context.luAction select a; // business logic and whatever else } } Which way is more efficient? Assume that you have two methods, one called DoSomething1() and another called DoSomething2(), and both methods incorporate the using statement to open the context and do whatever with it. Were you to call one method after the other, would there be any superfluous overhead going on, since essentially both methods create the context and then clean it up when they're done? As opposed to having just one private attribute that is created when a class object is instantiated, and then in turn cleaned up when the object goes out of scope?

    Read the article

  • How do I Relate these 4 Tables

    - by Baddie
    Trying to setup a simple Thread/Poll table mapping. Here is what I have: Threads table ThreadID (Primary Key/Identity Column) Polls table PollID (Primary Key, FK for ThreadID for one-to-one relation) Question PollOptions table PollOptionID (Identity/Primary Key) Text PollID PollVotes table PollVoteID (Primary Key/Identity) PollOptionID I'm not sure if this is a proper relationship. It seems wrong but I'm not sure whats wrong with it. A Thread can have 0 or 1 Poll. A Poll can have 2 or more PollOptions. A PollOption can have 0 or many PollVotes. I'm going to be using Entity Framework and before I generate the code for it (VS 2010, .NET 4) I want to make sure I have the proper relationship mapping.

    Read the article

  • Is there an ORM with APIs to be used programatically?

    - by Kabeer
    Hello. Neither did not get any response for my previous question, nor enough views :) So here I am now framing my query afresh. Is there any ORM that offers APIs to be used programatically? In my situation, a user will be helped through a wizard to define some entities. Thereafter those entites will be created in a database in form of tables (there will of course be some improvization). I need an ORM that offers APIs for modeling and creating entities during application runtime and not just during design time. Mine is a .Net application, therefore I was looking at Entity Framework. However, to me it looked tied to Visual Studio (I may be wrong also as I am new to it). Any recommendations? Or alternative point of view?

    Read the article

  • A generic Find method to search by Guid type for class implementing IDbSet interface

    - by imak
    I am implementing a FakeDataSet class by implementing IDbSet interface. As part of implementing this interface, I have to implement Find method. All my entity classes has an Guid type Id column. I am trying to implement Find method for this FakeDbSet class but having hard time to write it in a generic way. Below is my attempts for writing this method but since it does not know about Id been Guid type, I am getting compilation error on m.Id call. Any ideas on how this could be accomplished? public class FakeDataSet<T> : IDbSet<T> where T: class, new() { // Other methods for implementing IDbSet interface public T Find(params object[] keyValues) { var keyValue = (Guid)keyValues.FirstOrDefault(); return this.SingleOrDefault(m => m.Id == keyValue); // How can I write this } }

    Read the article

< Previous Page | 25 26 27 28 29 30 31 32 33 34 35 36  | Next Page >