Entity Framework 6 - Knowledge Base (KB)

Multiple relationship binding with EntityDataSource

I have an ADO .Net Entity Data Model for my database. In this Model I have three related tables: "Users" Table containing UserId and other details. "Run" Table that contains RunId, ApproverId and other details "RunToUser" that contains UserId and RunId c...

Getting Error 3007 when I add my Entity Model

I am getting an error 3007 when I add my entity model to my solution....I found these links:...Good explination...Short answer...About this error:...Error 1 Error 3007: Problem in Mapping Fragments starting at lines 89, 94: Non-Primary-Key column(s)...

Insert record using entity Framework (database first)

there are 3 database tables (movies, reviews, users)...the reviews table include ( MemeberID, MovieID, Review Text, Rate, ReviewDate) (the MemeberID, and MovieID in the Review are the FK of the members table and the movies table) The Movie can have many r...

InnerException in Entity Framework when I try add an entity

I'm trying to insert a entity into my database with Entity Framework. See below:...private void InsertarIntoDataBase() { Juego game = db.games.First(g => g.Id == anId); Day d = new Day { DayNumber = this.Number, ...

Implementing Zero Or One to Zero Or One relationship in EF Code first by Fluent API

I have two POCO classes...public class Order { int id; string code; int? quotationId; //it is foreign key public int Id{get;set;} public string Code{get;set;} public int? QuotationId{get;set;} Quotation quotation; public v...

MapKey vs HasForeignKey Difference - Fluent Api

What is actually the difference between:...this.HasRequired(a => a.Something) .WithMany() .Map(a => a.MapKey("SomethingId")); ...and...this.HasRequired(a => a.Something) .WithMany() .HasForeignKey(a => a.SomethingId);

Entity Relationship Diagram for Hotel

I need to create an ERD for a hotel, the question reads as follows:..."...The owner of a set of hotels would like to have a hotel management system built for his or her hotels. The hotels are located in major cities and tourist attraction areas of South ...

How to create Lookup table and define relationships

As you can see at below, there are a Lookup table for the enum values and I want to create a relationship between a table's enum values and ...LookupKey... column of the Lookup table (instead of ID column of the Lookup table). ...Lookup table:...ID | Lo...

Plymorphic Many to Many relationships in EF

I have a polymorphic collection on one entity type that contains a collection of objects that are the child types of it. the child types are all stored in different tables in the db. ...I need to map this relationship in the fluent API so I can manage the...

Entity Framework - Invalid Column Name 'User_ID"

I have a project written with ...C#... on the top of ASP.NET MVC 5 framework. I am using Entity Framework 6.2 ORM to interact with my database....I have the following 2 entity classes...public class User { [Key] public int Id { get; set;} publ...