ef-code-first

问题 I have a class Email that looks like : public class Email { [DatabaseGenerated(DatabaseGeneratedOption.Identity)] public int Id { get; set; } public string Subject { get; set; } public string Body { get; set; } public string From { get; set; } public DateTime SentOn { get; set; } public List<string> To { get; set; } } To ensure uniqueness I made a compound key on Subject , From and SentOn This created the problem that when Subject excess 128 characters, validation fails. So I just put a

问题 I have objects in their own tables using EF Codefirst. Now I try to produce an "archive" for changed objects living in separate tables for each of those objects. For instance: public class Person { [Key] public virtual Guid Id { get; set; } [Required] public string Name { get; set; } } public class Person_Archive : Person { [Key] [Columnn( Order = 1 )] public override Guid Id { get; set; } [Key] [Columnn( Order = 2 )] public DateTime ChangedAt { get; set; } public string ChangedBy { get; set;

问题 I want to know whether EF CodeFirst will automatically track "child" objects in the example below. var db = MyDataContext(); var order = db.Orders.Find(orderId); order.AddOrderLine("Fancy Product"); db.Commit(); Here are my (simplified) domain entities public class OrderLine { public Guid OrderLineId { get; private set; } public Guid OrderId { get; private set; } public string Description { get; private set; } public OrderLine(Guid orderId, string description) { OrderLineId = Guid.NewGuid();

问题 This seems like it should be so easy, but I've tried three or four ways to do it (but to no avail). I'm just trying to put a query result in a viewbag and display it. I've tried putting a model object list in a ViewBag: var mesg = from MSG in lemondb.Messages where MSG.msg == Membership.GetUser().ToString() select MSG; ViewBag.messages = MSG; And then I try to spit it out in a .cshtml: var message = (List<LemonTrader.Models.Message>)ViewBag.messages; // <--- fails here because it is a string

问题 I want my domain class name to match my db table name (no pluralisation). In EF Core 1.1, I used this code to do that: public static void RemovePluralisingTableNameConvention(this ModelBuilder modelBuilder) { foreach (IMutableEntityType entityType in modelBuilder.Model.GetEntityTypes()) { entityType.Relational().TableName = entityType.DisplayName(); } } In EF Core 2.0, this code doesn't compile as Relational() is not a method on IMutableEntityType. Anyway, in EF Core 2.0, they have added

问题 I am currently using TopShelf with Ninject to create a Windows Service. I have the following code to setup the Windows Service using TopShelf: static void Main(string[] args) { using (IKernel kernel = new StandardKernel(new NinjectDependencyResolver())) { Settings settings = kernel.Get<Settings>(); var host = HostFactory.New(x => { x.Service<BotService>(s => { s.ConstructUsing(name => new BotService(settings.Service.TimeInterval)); s.WhenStarted(ms => ms.Start()); s.WhenStopped(ms => ms.Stop(

问题 I am having a very hard time in using the SQLite db with EF CTP5. I was just trying to execute this MSDN example with SQLite. But at the line var food = db.Categories.Find("FOOD"); I am getting a runtime exception: System.Data.SQLite.SQLiteException (0x80004005): SQLite errorno such table: Categories Note: The app.config file has to be modified and is as follows: App.config <configuration> <startup useLegacyV2RuntimeActivationPolicy="true"> <supportedRuntime version="v4.0" /> </startup>

问题 i'm having some problems with entity framework and a sql database. so my problem is this: in my database there are two tables that have the same property, they are identical in type and length but they are not related in any way. no foreign key whatsoever. as soon as i start to interact with the database entity framework spits out the famous error: error 0019: Each property name in a type must be unique. Property name was already defined. i'm using the code first approach by the way. this is

问题 I have a generic repository implementation. I'm using asp.net mvc c#, code first entity framework. I created an interface named ISoftDelete: public interface ISoftDelete { bool IsDeleted { get; set; } } I implemented Delete and GetById in my base repository as follows: public virtual void Delete(T entity) { if (entity is ISoftDelete) { ((ISoftDelete)entity).IsDeleted = true; } else { dbset.Remove(entity); } } public virtual T GetById(long id) { T obj = dbset.Find(id); if (obj is ISoftDelete)

问题 I have a lookup table and a data table in my db. I'll use gender and person for an example. So let's say the gender table looks like so: Id Code 1 Male 2 Female and the person table looks like so: Id Name GenderId 1 Bob 1 2 Jane 2 I've modelled both tables in EF code first like so: public class Gender { public int Id {get;set;} public string Code {get;set;} } public class Person { public int Id {get;set;} public string Name {get;set;} public int GenderId {get;set;} public virtual Gender {get