entity-framework-4.1

问题 We have a scenario in our unit tests where we have created a FakeDbSet that implements IDbSet. In a FakeUnitOfwork I have properties that are IDbSets and getting new-ed up using the FakeDbSet. Without having to write out each different property in my Commit method I am trying to use reflection to iterate over the properties inside the FakeUnitOfWork. I then want to copy the property values to a differnt class that has propertes of List<> of the same type. So I may have a property in my

问题 I have a model hierarchy configuration like so: [Table("A")] abstract class A { } class B : A { } // treated as abstract [Table("C")] class C : B { } This results in a TPH for A and B, and a TPT for C. So far this seems to work fine. There are two database tables being generated: "A" which contains both A and B model records, and "C" which contains only C model record columns not already kept in table "A". For the TPH arrangement on Table A, there is a generated "Discriminator" column, which

问题 i'm using entity framework data migrations. if i change something about entites or something else, i try to use " add-migration MyFirstMigration " on Package Manager Console. But it returns an exception : The term 'add-migration' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was inclu ded, verify that the path is correct and try again. At line:1 char:14 + add-migration <<<< + CategoryInfo : ObjectNotFound:

问题 I am implementing feature that allows users to follow each other. I have database tables: User{UserId, FirstName, LastName etc.} Followings{FollowerUserId, FollowingUserId, CreatedOnDate etc.} So I added EF class: public class Follow { [Key, Column(Order = 1)] public Guid FollowerUserId { get; set; } [Key, Column(Order = 2)] public Guid FollowUserId { get; set; } public DateTime CreatedOnDate { get; set; } public virtual User Follower { get; set; } public virtual User Following { get; set; }

问题 I am implementing feature that allows users to follow each other. I have database tables: User{UserId, FirstName, LastName etc.} Followings{FollowerUserId, FollowingUserId, CreatedOnDate etc.} So I added EF class: public class Follow { [Key, Column(Order = 1)] public Guid FollowerUserId { get; set; } [Key, Column(Order = 2)] public Guid FollowUserId { get; set; } public DateTime CreatedOnDate { get; set; } public virtual User Follower { get; set; } public virtual User Following { get; set; }

问题 I am getting this error message when using EF 4.1 code first approach with Sql compact 4. I don't see any model who has id column more than one so i have no idea why this error occured. What can cause this error ? Edit : I want to specifiy few extra things. Database creating is success but model creating is not. And Exception has been thrown from sqlce methods. 回答1: This issue stems from a SQL query that returns two or more columns that have an identical name. SQL will handle exact duplicate

问题 I'm using Entity Framework 4.1 RC and code first approach. How can I call custom SQL functions? If I use EdmFunction attribute, what namespace should I specify? [EdmFunction("Namespace", "GetAge")] public static int GetAge(Person p) { throw new NotSupportedException(…); } When I try to execute a LINQ query with such function the following exception is thrown: The specified method '...' on the type '...' cannot be translated into a LINQ to Entities store expression. 回答1: If you want to call

问题 I want to change Collation of the whole database created by ef code first, I try to do it by running a script after creation but it does not works, _dbContext.Database.Delete(); _dbContext.Database.CreateIfNotExists(); _dbContext.Database.ExecuteSqlCommand("ALTER DATABASE afi COLLATE French_CI_AI"); Is it possible to set the collation before creating the database? That is the exception I get : Resetting the connection results in a different state than the initial login. The login fails. Login

问题 I have an extension method as follows: public static bool SatisfiesSomeCondition(this Post post, SomeObj someObj) { return post.SomeObjId == someObj.SomeObjId; } And i'm trying to use it like this: var query = ctx.Posts.Where(p => p.SatisfiesSomeCondition(someObj)).ToList(); But i get the error: LINQ to Entities does not recognize the method 'Boolean SatisfiesSomeCondition(xx.xx.xx.Post, xx.xx.xx.SomeObj)' method, and this method cannot be translated into a store expression. If i change the

问题 I'm using Entity Framework and MVC3, I have used Model First approch... I have used Company as a Base class and I have inherited the Lead Class from it. When I run the application its gives an error... This is Base Class using System; using System.Collections.Generic; namespace CRMEntities { public partial class Company { public int Id { get; set; } } } This is Lead Class (Child) using System; using System.Collections.Generic; namespace CRMEntities { public partial class Lead : Company {