ef-code-first

问题 Having a strange issue working on a code first EF project. I have the following entities: public class Booking { public Guid BookingId { get; set; } public virtual List<AccountingDocumentItem> AccountingDocumentItems { get; set; } } public class AccountingDocumentItem { public Guid AccountingDocumentItemId { get; set; } public virtual List<Employee> Employees { get; set; } public virtual List<Booking> Bookings { get; set; } } public class Employee { public Guid EmployeeId { get; set; } public

问题 Not having a great time with doing EF Core Reverse Engineering. Latest error The method or operation is not implemented. Scaffold-DbContext "The method or operation is not implemented" i get the same errors for both of these commands Running this from Package Manager Console within VS 2017: Scaffold-DbContext 'Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=Chinook' Microsoft.EntityFrameworkCore.SqlServer and from command prompt: dotnet ef dbcontext scaffold "Data Source=(localdb)

问题 I want to make a query that'll return me entities and additionally a number of one of their associated entities. For example: select *, (select COUNT(*) from Forms where Contact_Id = Contacts.Id) as FormsCount from Contacts; My Contact entity has a property named FormsCount, but it isn't mapped since there's no column named like that in the table. Is it possible to write one LINQ query that'll return me Contact entities with the additional FormsCount property filled in? Alternatively, I'd be

问题 So, I have followed this instruction from ADO.NET team blog to try to make a small test project. I have double-checked everything. It doesn't seem to work and keeps saying connection string is missing. http://blogs.msdn.com/b/adonet/archive/2011/03/15/ef-4-1-model-amp-database-first-walkthrough.aspx Step. 1 Build this UserModels.dll. In the dll, App.Config file, edmx generated this connection string: (hit the 'test' button when making it, and it connects successfully, and generated the edmx

问题 I have a database with the Entity Framework 5 RC (with Fluent API) working now, but I can't seem to get a specific relation to work. And it is driving me nuts for the past few nights I'm working on it. It is the following relation: Link to the database diagram As you can see, I have a Exercise which is related to an ExerciseType . The problem is, the Exercise.ExerciseType navigation property, is not loaded. The relation I made is as follows: EntityTypeConfiguration<Exercise> ... this

问题 When I try to load child entity of parent entity it loads with default values. If i try to load explicitly it throws exception Multiplicity constraint violated . The role 'Association_Customer_Target' of the relationship 'CodeFirstNamespace.Association_Customer' has multiplicity 1 or 0..1. This exception is thrown while retrieving the child entities of a complex graph. I have a graph Association which has a child entity Customer with a relationship of one to zero or one and has an Independent

问题 I was getting the following error when runing such this code: var dbContext = new MyDbContext(); var list = dbContext.Set<TEntity>().ToList(); From the changes I made recently to codes I understood that because I added an event to the base class it causes all the problems: public PropertyChangedEventHandler PropertyChangedEvent { get; set; } Applying the NotMapped attribute to the above property my codes now are working again. Now I want to know if there is anyway to autmatically tell

问题 My database model (sometimes referred to as " context ") is dynamically assembled at startup based on which services and/or plugins are installed. Plugins and services export their model definition fragments through my IoC container and the application core picks them up and runs them when the DbContext.OnModelCreating method is called. The question is: Can I (and how do I) use Code First Migrations with this setup ? (below is more information on what I've tried and what particular problems

问题 So I either get errors firing or nothing happens. I know that I have custom Entity Framework Initializer like this: using System; using System.Collections.Generic; using System.Data.Entity; using System.Linq; using System.Text; using System.Threading.Tasks; namespace EasyEntity { public class EasyInitializer : DropCreateDatabaseAlways<EasyContext> { protected override void Seed(EasyContext context) { List<Person> persons = new List<Person> { new Person { FirstName = "Waz", LastName = "Amattau

问题 For a program I'm using EF code first for the first time. In the past I used linq to SQL en EF DbFirst. When retreiving the main record'I'm unable to load the subrecords using the navigational properties. I get an empty subrecord with all record-fields are 0 or null. When I want to apply eager loading. the .Include(x=>x.......) isn't showing my navigationals. I have set up the following classes: public Record() { Shipping = new ShippingData(); Delivery = new DeliveryData(); Items = new List