dbcontext

问题 I don't know if I'm doing something wrong here or not... As a bit of background, I am working on an Entity Framework (v5.0) solution and was looking to add extra functionality to the DBContext class, so any tt-generated classes (that inherit from DbContext) will have that inherent functionality available to them automatically. Based upon the answer I saw here, I figured it would be as easy as simply adding in a new class that would look as follows: Imports System.Data.Entity Imports System

问题 I have a .net core app. I write my connection string in appsettings.json file. But, now, I want to get that connection string for my context. How to do that? In .net framework 4.6 I used this: ConfigurationManager.ConnectionStrings["ConnStrName"].ConnectionString; I have appsettings.Development.json like this (*** could be any name): "ConnectionStrings": { "***": "Server=***;Database=****;Trusted_Connection=True;MultipleActiveResultSets=true;" } I added service: services.AddTransient

问题 I am using the new Test Doubles in EF6 as outlined here from MSDN . VS2013 with Moq & nUnit. All was good until I had to do something like this: var myFoo = context.Foos.Find(id); and then: myFoo.Name = "Bar"; and then : context.Entry(myFoo).Property("Name").IsModified = true; At this point is where I get an error: Additional information: Member 'IsModified' cannot be called for property 'Name' because the entity of type 'Foo' does not exist in the context. To add an entity to the context

问题 Problem: When adding an object "Order" to my dbcontext, all nested objects of the order gets "readded" to the database, though the nested objects is static data and only a reference shoudl be added in the database. Example: The database holds 0 orders, and 3 items. I add one order with 2 items. Now the database hold 1 order, and 5 items. The two items in the order has been "readded" to the database, even though the items had the right primary keys before db.SaveChanges(). I realize that i may

问题 here's my question: I have an MVC3 C# application and I need to update a value in a DbSet from the Edit controller, so the T item's value will be replaced with a new one. I don't want to delete the item and add it again. I cannot figure out how to do this. DbSet doesn't seem to have something like an index. Here's my Edit controller: public class ItemController : Controller { private SESOContext db = new SESOContext(); private FindQrs fqr = new FindQrs(); [HttpPost] public ActionResult Edit

问题 I have just created an ASP.NET MVC 4 & WebAPI project. After that I have added .edmx data source to project. I have multiple databases with the same schema. Dynamically I want to replace connection string using default constructor provided in EF. But in Model1.Designer.cs , every time I get error like "Member with same signature already declared". I'm unable to solve this problem. 回答1: Yes, it works! All you need to change is the connection string . And I have just tested it in order to

问题 We have a plethora of databases all sharing the same schema. They are spread about on a number of SQL Servers, some 2005, some 2008. We are getting an exception when connecting to a 2005 server AFTER having connected to a 2008 server first stating the following: An error occurred while updating the entries. See the inner exception for details. An error occurred while updating the entries. See the inner exception for details. The version of SQL Server in use does not support datatype

问题 Given a DbContext that implements 2 interfaces like so: public interface IQueryEntities { IQueryable<User> Users { get; } IQueryable<Computer> Computers { get; } // other IQueryable<T> get properties } public interface IUnitOfWork { int SaveChanges(); } public class MyContext : DbContext, IQueryEntities, IUnitOfWork { // implement interfaces using EF } First question, is it a bad idea to separate out the query aspects of DbContext (IDbSets) from the command aspects (SaveChanges)? I am

问题 I am writing unit tests for my Generic Repository layer but i have some problems with DbEntityEntry . My Update method is like below. public virtual void Update(TEntity entityToUpdate) { var entity = dbSet.Find(context.Entry<ITrackedEntity>(entityToUpdate).Entity.Id); context.Entry(entity).CurrentValues.SetValues(entityToUpdate); } As you can see, context.Entry<TEntity>(TEntity entity) method is invoked by caller. So while unit tests this code throws null exception. I had tried to mock

问题 We have a huge database with 770 tables and want to do some performance testing with EF 6.1x. We want to query only 5 of those 770 tables. Is it possible to create a "light" DBContext with only 5-6 entities/DBSets instead of using the full 770-tables-context? When we use the full context, a simple query with 4 joins takes 45 seconds. Thats' 44 seconds too long. We are using code-first (reverse engineered). The problem: When we create such a "light" version of the full context (i.e. 5 tables