entity-framework-core

问题 I've upgraded to Visual Studio Code 1.0.0 and I'm trying to retrofit an ASP.NET Core project I was working on in VSCode previously, before the new release. VSCode is seemingly quite different now in terms of configuration. I've worked with this tutorial and these samples. I'm having reasonable success getting the MVC6 aspect of my project compiling and working properly, but the EntityFramework 7 aspect is a no-go. When I do a dotnet restore on my project, I get the following error: Package

问题 I have the following code that I am trying to update ClientAccount using ef core but they Concurrency Check fails: public class ClientAccount { [Key] [DatabaseGenerated(DatabaseGeneratedOption.Identity)] public long Id { get; set; } [Required] [ConcurrencyCheck] public double Balance { get; set; } [Required] public DateTime DateTimeCreated { get; set; } [Required] public DateTime DateTimeUpdated { get; set; } } public class ClientRepository { private readonly MyContext context; public

问题 We need to ensure that EF Core-based code has performed a specific kind of database-level operation under test (for example, any command execution or any transaction commit). Let's suppose a real database should be triggered and we can't isolate it by DbContext mocking. How could it look: [Fact] public async Task Test() { using (var context = new FooContext()) { //context-related code to produce queries and commands } Assert.True(/* any context-related transaction has been committed */); } Is

问题 My model contains the classes Post and PostHistory, where Post has a one-to-many relationship with PostHistory. class Post { public int Id { get; set; } public PostVersion CurrentVersion { get; set; } public PostVersion OriginalVersion { get; set; } public IList<PostVersion> History { get; set; } } class PostVersion { public int Id { get; set; } public Post Post { get; set; } public string Title { get; set; } public string Body { get; set; } } The History property contains a list of all

问题 On my Entity Framework Core project I've a generic repository with a GetAll() method public ICollection<Entity> GetAll(){ return DbSet.ToList(); } But when I execute it, throws the following: System.MissingMethodException was unhandled HResult=-2146233069 Message=Method not found: 'Void Microsoft.EntityFrameworkCore.Query.QueryContextFactory..ctor(Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IStateManager, Microsoft.EntityFrameworkCore.Internal.IConcurrencyDetector, Microsoft

问题 Very quick question : I'm trying to create a predicate builder like this : var predicate = PredicateBuilder.False<MyObject>(); But seems that is not available in Net Core And EF Core . Am I missing a package or something ? 回答1: Are you sure that the PredicateBuilder you were using was not a custom class? A PredicateBuilder is shipped as part of LINQKit but the source is also available here as follows: public static class PredicateBuilder { public static Expression<Func<T, bool>> True<T>() {

问题 I am trying to scaffold and getting following error: There was an error running the selected code generator Method not found: 'Void EntityFrameworkCore.Design.Internal.DbContextOperations 回答1: https://docs.microsoft.com/en-us/ef/core/get-started/aspnetcore/existing-db?view=aspnetcore-2.0#install-entity-framework I suspect you are missing the assemblies that are necessary for scaffolding? I also assume you are trying to reverse engineer an existing db? example Scaffold-DbContext "Server=

问题 I've been unable to validate models generated by the Scaffold-DbContext command in my ASP.NET Core controllers. The required/max length property configurations are all in the onModelCreating method of the context class that EF core generated. protected override void OnModelCreating( ModelBuilder modelBuilder ) { modelBuilder.Entity<ModelClass>( entity => { entity.ToTable( "ModelClass", "schema" ); entity.Property( e => e.ModelClassCode ) .IsRequired() .HasMaxLength( 30 ); My controller

问题 The relation between Product and Customer is of type many-to-many (from a design point a view). Using EF Core, we split this relation in two one-to-many relations with a third entity: ProductCustomer public partial class ProductCustomer { public long ProductId { get; set; } public long CustomerId { get; set; } public virtual Customer Customer { get; set; } public virtual Product Product { get; set; } public virtual ICollection<UsageRecord> UsageRecord { get; set; } } UsageRecord is a list of

问题 I'm using Entity Framework and .Net Core 2.0 for the first time (I'm also pretty new to C#, but I've been using the traditional .Net Framework & VB since version 1... so I'm no newbie to .Net development), and I've already run into a problem creating my database. Take this simple scenario: I want to store some information about some electric pumps. Two of the properties are a min/max type range, so I've implemented these as a simple class, thus: public class Pump { [Key] public int pumpId {