Entity Framework Core - Knowledge Base (KB)
6642 results
EF Core - System.InvalidOperationException: ExecuteReader requires an open and available Connection. The connection's current state is closed
I'm running an ASP.NET Core 1.0 web app with Entity Framework Core. When the app has been running for a while (24 - 48 hours), the app starts crashing on every request to any endpoint or static resource throwing the error ...System.InvalidOperationExcepti...
asked by severin
Cannot access a disposed object in ASP.NET Core when injecting DbContext
On an ASP.NET Core project I have the following on Startup:... services.AddDbContext<Context>(x => x.UseSqlServer(connectionString)); services.AddTransient<IValidationService, ValidationService>(); services.AddTransient<IValidator<Model>, ModelVali...
asked by Miguel Moura
Add migration with different assembly
I am working on a project with ASP.NET CORE 1.0.0 and I am using EntityFrameworkCore. I have separate assemblies and my project structure looks like this:...ProjectSolution -src -1 Domain -Project.Data -2 Api -Project.Api ...
asked by kdar
"A dependent property in a ReferentialConstraint is mapped to a store-generated column." on a persisted computed column (EntityFramework DB first)
I've implemented a simulated table inheritance construct in my SQL-Server based on the article ...Implementing Table Inheritance in SQL Server.... ...Besides the fact to use simple 1 to 0...1 relationships you create another constraint to a type table tha...
asked by Martin Braun
Could not load type ServiceCollectionExtensions
I'm working with ASP.NET Core 1.0 and trying to configure my DbContext for migrations. I got this exception:...Could not load type 'Microsoft.Extensions.DependencyInjection.Extensions.ServiceCollectionExtensions' from assembly 'Microsoft.Extensions.Depend...
asked by Emmanuel Villegas
ASP.NET Core only returning first value of a collection in an entity
I have a class MyEntity with a collection within it:...public class MyEntity { [Key] public int MyId { get; set; } [Display(Name = "Process Name")] public string ProcessName { get; set; } public ICollection<Step> ProcessSteps { get...
asked by vasa.dhananjay
How to update the model when using database first approach
I used EntityFramework Core database first to create model ...as illustrated in the EF Core documentation...But I don't know how to update the model when the database has been edit.
asked by witson
Get custom property of signed in user in .NET Core
I'm working on a .NET Core project and I have added a custom column to the ...ASPNetUsers... table called ...DisplayName... that users set during the registration. I've successfully migrated the tables with that data and everything works fine....However ...
asked by DethoRhyne
How to generate an entity model from a query w/ EntityFrameworkCore
I'm trying to connect an ASP.NET Core web application to an existing, pretty complex database, in read-only mode....The database is much to complex to map its layout to EFC directly, I just access data from it via a set of queries. Those queries are well-...
asked by Johann Studanski
Mocking DbContext in Entity Framework 6.1
I have found a number of examples that show (apparently) a clear working example of mocking DbContext with EF 6, however, none of them seem to work for me and I am not entirely sure why....This is my unit test code that sets up the mock;...var mockData = ...
asked by ChrisBint
.net core and ef core sql server error provider: SQL Network Interfaces, error: 8 - Protocol not supported
I've been trying to develop a new application using .net core in MacOsX using a SQL Server database, but i'm having some problems with the connection because i'm getting the following error:...fail: Microsoft.AspNetCore.Server.Kestrel[13] Connecti...
asked by Leobardo Mora Castro
Including only Id of related entity in entity framework core
I am currently developing an API with ASP.NET Core and Entity framework core with npgsql as database provider. I have two Entities and they have a one to many relation. The thing is that I only want to include the Id's of the child entity in the JSON resu...
asked by larzz11
How do I visually design my database with Entity Framework Core?
I am wondering myself, how I should design my database scheme (in terms of efficiency and visuality)....I am developing a ASP.NET Core application with Angular 2 and I am using ...Entity Framework Core... (..."Microsoft.EntityFrameworkCore": "1.0.0"...), ...
asked by WoIIe
Modelling folder structure in Entity Framework Core
I would like to save an hierarchical folder structure into a SQL database. The class would like this:...public class Folder { public Folder() { Children = new List<Folder>(); } public string Name { get; set; } public int Id {...
asked by RBasniak
Entity Framework: Foreign Key in code first
What is wrong in my code that i get below error:...Unable to determine a valid ordering for dependent operations. Dependencies may exist due to foreign key constraints, model requirements, or store-generated values...Code:...Class Food:...public class Foo...
asked by Ali Mottaghi Pour
Configuring DbContext Constructor
I'm trying to use EF Core tools to manage an SqlServer database I'm designing in a C# class library. It's in a class library because I need to use the database schema in both an MVC6 website and some command line tools....I had to convert the class librar...
asked by Mark Olbert
How to build several left join query in Entity Framework Core
Consider i have below entities:... public class Root { public long Id { get; set; } } public class School : Root { public long StudentId { get; set; } public Student Student { get; set; } public Teacher ...
asked by dimitri
UWP / EF Core SqlServer - Threading Dependency
I'm attempting to use Microsoft.EntityFrameworkCore.SqlServer, but I appear to not have an appropriate Threading dependency. When using NuGet to attempt to install EF Core SS, I get several messages like the following:...Restoring packages for c:\visual s...
asked by TRAL
Using ToListAsync() with Automapper ProjectToQueryable()
I have a sync method which I'm trying to convert to async. Basically, the code below projects the data into a DTO, and selects rows and orders them based on properties of the DTO. It also gets only a certain 'page' of the data....return GetDbContext().Ite...
asked by Frank Fajardo
How to add EntityObject Generator in Visual Studio 2015?
I have installed the latest Entity Framework version (EntityFramework.6.1.3) in VS2015. I have added the EF in the project and deleted the 2 .tt files (...edmx_file_name.tt... and ...edmx_file_name.Context.tt...) as they were from the DBContext. ...Now I ...
asked by Makesh Arinha Valappil
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