I am searching for a way to globally disable change tracking in my Context class. This will prevent developers from forgetting to put .AsNoTracking() on each repository query as we currently do. This will also prevent us from manually having to .Detach() entities on occasion. I have found a solution in EF Core which is to do something like the following:
public class MyContext : DbContext
{
public MyContext() {
ChangeTracker.QueryTrackingBehavior =
QueryTrackingBehavior.NoTracking;
}
public DbSet<MyEntity> MyEntities {get;set;}
}
However, the Context class in Entity Framework 6 does not appear to have a QueryTrackingBehavior property on it's ChangeTracker. Is there a way to accomplish this using Entity Framework 6?
Please note that I have already looked into using AutoDetectChangesEnabled = false and it does not work for the reasons outlined here.
All help is appreciated.
No, there is no similar functionality in EF6
Related
I'm fairly new to asp.net mvc, so please bear with me.
I want to implement a calendar functionality, and all the tutorials I've looked at use database-first approach and have the edmx file (Entity Data Model)
I'm using code first and what can I do regarding the code that references this edmx file? do I reference context instead?
example:
public JsonResult GetEvents()
{
//Here MyDatabaseEntities is our entity datacontext (see Step 4)
using (MyDatabaseEntities dc = new MyDatabaseEntities())
{
var v = dc.Events.OrderBy(a => a.StartAt).ToList();
return new JsonResult { Data = v, JsonRequestBehavior = JsonRequestBehavior.AllowGet };
}
}
Sorry if this question is vague or not clear.
Thank you and I'd appreciate help!
In code first, you don't need an edmx file, because everything is in your own code. The basic building blocks are:
A class that inherits from DbContext. This will be equivalent to the MyDatabaseEntities class in your sample.
A set of entity classes. They basically just need to be plain classes with auto properties corresponding to your database columns. For built in conventions to work, you also need an ID, for instance an int property named Id
A set of properties on your DbContext class of type DbSet for every type T which is an entity you would like to query against. This is the Events property in your example.
In more advanced scenarios you customize the mappings beyond what the conventions can infer automatically. This can be done with attributes on your entity classes, or via a special set of APIs that can be called on your context at startup
Go to Sql server inside your database there is a folder Database Diagram, Right click New Database Diagram and explore it.
Recently i tried to create a MVC application using ASP.NET Core 2.0 and i had some values defined in appsettings.json,
"MySettings": {
"WebApiBaseUrl": "http://localhost:6846/api/"
}
In order to read these values i have added
services.Configure<MySettingsModel>(Configuration.GetSection("MySettings"));
above line in ConfigureServices method in Startup.cs
and in my home controller i have added
private readonly IOptions<MySettingsModel> appSettings;
public HomeController(IOptions<MySettingsModel> app)
{
appSettings = app;
}
MySettingsModel class is just a model with property same as key define in appsettings.json.
by this method i'm able to read the value of this key.
Now my issue is that i want to use this key in many controllers so i don't want to repeat this code in every controller so what i did was i created a BaseConntroller, added its constructor and i got my values there. But when i inherit other controllers with my BaseController , it throws me an error and tells me to generate it's constructor, so basically it tells me to add constructor in every controller which is what i wanted to avoid.
How can i achieve this?
You can see the image for the error
And these are the potential fixes that it shows me.
This is just basic C# inheritance. Derived classes must re-implement constructors on base classes (at least the ones you want or need). The only exception is the empty constructor, which is implicit. In other words, you simply need:
public class HomeController : BaseController
{
public HomeController(IOptions<MySettingsModel> app)
: base(app)
{
}
And, of course, you need to change the accessibility of the base class field to protected instead of private. Otherwise, derived classes will not be able to access it.
Of course, this doesn't really save you that much. However, there's no free lunch here. Like I said, this is a limitation of C#, itself, so you have no choice. Although, it's worth mentioning, that while this can sometimes be annoying, it's actually a kind of useful feature of C#. You can look at any class and see exactly what constructors it has available, without having to trace down all its ancestors.
Actually, there is a good solution here:
https://stackoverflow.com/a/48886242/2060975
I am mostly using this method.
[Authorize]
[ApiController]
public abstract class ApiControllerBase : ControllerBase
{
private IOptions<AppSettings> _appSettings;
protected IOptions<AppSettings> appSettings => _appSettings ?? (_appSettings = (IOptions<AppSettings>)this.HttpContext.RequestServices.GetService(typeof(IOptions<AppSettings>)));
...
}
I hope it helps someone:)
My first question on SO!
What I'm working on is a Webforms page that's has a lot ASP textboxes, datepickers and dropdowns. Right now I'm using ADO.net for all of these controls to do CRUD operations.
I'm already a great deal into this project, but I can't help wondering if I could be doing this in an easier or more efficient way. So far I'm using the SqlDataReader class for everything.
If someone could break down the different options available to me or point me to some good information, I'd appreciate it. I know it's a pretty broad topic. I'm kind of aware of LINQtoSQL and EntityFramework.
So my question really is: How does ADO.net compare to LINQtoSQL or EntityFramework?
you should read up on one sample each of ADO.NET, Linq 2 SQL and Entity Framework and implement them to know the pros/cons of each. a simple web search should give you samples.
Linq2Sql and EF will require very SQL query writing from you. once you have an initial grasp of these 3 things individually, follow this simple pattern in your code:
define an interface for your data access.
let your code behind (ascx.cs and aspx.cs) work with the interface.
define concrete implementations of the interface based on ADO.NET, Linq2Sql or EF.
e.g.
public interface IRepository
{
MyDto GetData(int id);
// and so on
}
public class EntityFrameworkRepository : IRepository
{
public MyDto GetData(int id)
{
using (var db = new MyDbContext())
{
var myDtoEntity = db.MyDtoEntity.FirstOrDefault(m => m.Id == id);
// extension method to transform DB objects into DTOs
return myDtoEntity.ToMyDto();
}
}
}
// similarly you can do:
public class Linq2SqlRepository : IRepository
{
// so on..
}
// now for all your aspx.cs pages: derive them from a base page,
// and in the base page
// have a variable like this, so that all pages have access to this.
public IRepository Repository {get; set;}
// you can have static instances as well for one time initialization.
// you can initialize the Repository with a particular concrete implementation
// or inject it. (if you're well versed with Dependency Injection)
using the above way, all your code will work off the Interface, and you just need to change one place if you decide to change the implementation.
Anyone know if the Moq functional syntax supports setups for Non-Public properties? I noticed that it doesn't work.
NOTE: This is for the functional syntax.
public class Foo
{
public virtual int FooProperty { get; protected set; }
}
This doesn't throw an error, but fails to mock FooProperty
Mock.Of<Foo>(x => x.FooProperty == 1);
The regular syntax works fine.
var mockFoo = new Mock<Foo>(); mockFoo.SetupGet(x=>x.FooProperty)
.Returns(1)
It might be worth looking at the Pex/Moles tool from Microsoft Research. Moles is used to create accessors for non-public stuff.
It will support mocking of internal properties if you add an assembly attribute to the assembly containing the class under test (add to AssemblyInfo.cs):
// This assembly is the default dynamic assembly generated Castle DynamicProxy,
// used by Moq. Paste in a single line.
[assembly: InternalsVisibleTo("DynamicProxyGenAssembly2")]
(You would also have to add an InternalsVisibleTo entry for your test project, of course.)
If you do this, you can mock any internal property in the assembly to which this is added. If you want to mock private or protected properties, I'm pretty sure there's no way to do that directly. If they're protected, you could create a Dummy inheritor and give it public methods or properties that access/manipulate its protected members. For private, there's really nothing you can do, I believe.
I'm trying to create a data access later using System.DirectoryServices. I'd like to use the MVC 2 framework and have all my views be mostly strongly-typed. Does anyone know any good way to this?
For example I started creating a Group Entity:
public class Group
{
public string DistinguishedName { get; set; }
public string GroupName { get; set; }
}
And an abstract interface:
public interface IGroupRepository
{
List<Group> Groups { get; }
}
I am confused about developing the GroupRepository using the system.directory services. Connecting to a SQL database is easy there are examples everywhere but I have no been able to find any using the System.directory sevices in conjunction with a class using MVC. Has anyone tried to do something like this? Any great would be
If you're on .NET 3.5 (and if you use MVC 2, chances are good you are), you should check out the new System.DirectoryServices.AccountManagement namespace which brings you lots of strong .NET classes and types for many of the directory objects you're dealing with on a regular basis - no need to re-invent the wheel (yet again!).
Check out this great article in MSDN magazine on how to use this S.DS.AM namespace:
Managing Directory Security Principals in the .NET Framework 3.5
Update: for reasons I don't totally understand, the simple approach of using a UserPrincipal as a model for a ASP.NET MVC view doesn't work - it seems as if ASP.NET MVC cannot "find" any properties on that object.
So the approach would have to be to do something like this:
grab your UserPrincipal (or DirectoryEntry) from Active Directory
define a separate ViewModel - this is just a class that holds properties, like first name, last name and so forth
you can either fill that ViewModel class yourself, or you can grab some help like AutoMapper to make mapping from UserPrincipal (DirectoryEntry) to your ViewModel easier
then display (or edit) your ViewModel class in a standard ASP.NET MVC view
handle any possible updates by transferring any changes back from the ViewModel to the "proper" object and persisting that object
It's a bit more involved than I'd like it to be - but I quite honestly don't see how else you can do this otherwise.