Entity Framework 6 - Knowledge Base (KB)
64 results in tag: c#-4.0
Delete Object and its related entities
Does anyone know how to delete an object and all of it's related entities....For example I have tables, Products, Category, ProductCategory and productDetails, the productCategory is joining table of both Product and Category....I have read from ...http:/...
asked by Waheed
complus Exception code -532462766
Using visual studio 2010, entity framework 4.0, ADO.NET POCO Entity Generator...On the code lines:...MecDbEnt.Domains.AddObject(subject);...MecDbEnt.SaveChanges(); (on this line)...the application throws follow exception:...complus exception code -53246...
asked by Masna
Get the first record of a group in LINQ?
Summary: How to get top 1 element in ...ordered... groups of data...I am trying to group by a CarId field , and then within each group, I want to sort on a DateTimeStamp field descending. The desired data would be for each Car give me the latest DateTime...
asked by RyBolt
EF4 Context.ApplyCurrentValues does not update current values
I have a entity that I retrieve as follows and is detached from the context:...ctx.Reviews.MergeOption = MergeOption.NoTracking; Review review = (from r in ctx.Reviews.Include("ReviewNotes") where r.ReviewID == reviewID ...
asked by Big Joe
General Questions about Entity Framework vs. Enterprise Library & a few others
Brief blurb,...My skill in .net has been called "innovative" but I would prefer it be exemplary. Basically, I need a mentor. I own the domain name codeologist.com and I am going to live up to that name but in order to do so I need a mentor & community. ...
asked by jetstreamin
How do i define Keys when working with "EF-Code First"?
I get a ModelValidationException (at the bottom) when working with "EF-Code First". It wants me to define a Key but I'm not sure what exactly it means......public class Unit { Guid id; String public_id; String name; bool deleted; }...
asked by gingerbreadboy
Entity Framework - Underlying data (in database) change notification
I'm using the Entity Framework to manipulate data in a database with success so far....However, I would like to have more than one application playing with the data at the same time (concurrent edition)....Is there a way to get notified when the data in t...
asked by Nicolas
What is the meaning of the "Pluralize or singularize generated object names" setting?
When setting up a new Entity data Model, there is an option to...[x] Pluralize or singularize generated object names...I have noticed this is an option in LINQ as well. Also, now that I am studying the ADO.NET entity framework, I noticed it also has 'DEFA...
asked by user287745
Mapping business Objects and Entity Object with reflection c#
I want to somehow map entity object to business object using reflection in c# - ...public class Category { public int CategoryID { get; set; } public string CategoryName { get; set; } } ...My Entity Class has same properties, Cat...
asked by Hidsman
String.Format in linq query
I am stuck on a wierd problem. I have a ...CashGameGeneralViewModel... class wich looks like this...public class CashGameGeneralViewModel { public string Limit { get; set; } public int HandsPlayed { get; set; } public float AmountWon { get; s...
asked by Ivan Crojach KaraÄić
How to use System.Lazy with Setter to Lazy Initialization of List in POCO Entities?
I want to use System.Lazy to Lazy Initialization of my List in my Entites:...public class Questionary { private Lazy<List<Question>> _questions = new Lazy<List<Question>>(() => new List<Question>()); public IList<Question> Questions { get { retur...
asked by Acaz Souza
Best Practices for MVC.. ViewModel Binding using Interfaces Example
I am new to ASP.NET MVC 3.0 and trying to build an application using the MVC ViewModel design.. ...I was wondering what the best practices are regrading controllers for ViewModels and have a few questions below.. This is my understanding so far (which mig...
asked by HonourCode
using Metadata with Entity Framework to validate using Data Annotation
I have a entity called Product,this is a part of it's declration:...[EdmEntityTypeAttribute(NamespaceName="NorthwindModel", Name="Product")] [Serializable()] [DataContractAttribute(IsReference=true)] public partial class Product : EntityObject { #regi...
asked by Arian
How to put an Entity Framework query result into a List
How to Put the following query result into a List...var result = from c in sb.Swithches_SW_PanalComponents select new { c.ID,c.SW_PanalComponents.ComponentsName,c.ComponentValue };
asked by major
How to "let" in lambda expression?
How can I rewrite this linq query to Entity on with lambda expression?... I want to use ...let... keyword or an equivalent in my lambda expression....var results = from store in Stores let AveragePrice = store.Sales.Average(s => s.Price) ...
asked by Reza Owliaei
How to Join two table in Code first approach
i have two table, User and Friendship. i want to join this two tables so that the column TheirFriends which have UserID of all friends will have some attribute that is in User. that is i want to get each friend with all their attribute. Output will look ...
asked by Johnson Duru
How to create dynamic condition using Expression Tree
Please consider this code:...System.Linq.Expressions.Expression<Func<tbl, bool>> exp_details = r => r.ID_Master == Id && r.Year == Year && r.Month == Month ; ...I want to write a function that expect some argument, and then retrieve some data from my data...
asked by Arian
Entity Exception : the underlying provider failed to open with Timeout expired
OK, I'm stumped. I am trying to create a .NET Winforms app to talk to a database via Entity Framework. I originally created a ASP.NET MVC3 app (with a seperate DAL layer) that can talk to the database after initially failing. SO the first time that it tri...
asked by Lutz Kretzschmar
converting iqueryable to IEnumerable
What is the problem with my code below.Its not returning any items even when matching records are present in db .if wrong how can I convert my IQueryable to IEnumerable ?...public IEnumerable<TimelineItem> TimeLineItems { get; set; } public IEnume...
asked by Renny
Entity Framework - CSDL, SSDL, and MSL files
I'm just being picky but I was researching how does Entity Framework generates the DLL from an EDMX file and I saw this on msdn:...The Entity Data Model Designer (Entity Designer) stores model and mapping information in an .edmx file at design time. At b...
asked by Diego
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