Entity Framework Core - Knowledge Base (KB)

Entity Framework 6 + SQLite

I'm trying to use EF6 alpha and SQLite 1.0.66.0...My .config file:...<connectionStrings> <add connectionString="data source=:memory:;" name="TestDbContext" providerName="System.Data.SQLite" /> </connectionStrings> <entityFramework> <providers> ...

Error: No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'

I recently upgraded/updated Entity Framework in an old project from version 4 or 5 to version 6. Now I get this exception:...An exception of type 'System.InvalidOperationException' occurred in EntityFramework.dll but was not handled in user code...Addit...

EF in WinForms: how to filter data in BindingSource/DGW (.Local.ToBindingList())

I generated an EF model (Database first) and DataSource following this tutorial ...http://msdn.microsoft.com/en-us/data/jj682076.aspx...On my form I created BindingSource (bsUsers) and bound DataGridView to it. ...Here is how I load data on form startup:....

Could EntityState.Modified cause Insert operation to be performed

I am reading the following tutorial about entity framework 6 ...Link.... And inside the section named ”Adding an Edit Page for Instructors”, the author wrote the following code inside the Post edit action method:-...[HttpPost, ActionName("Edit")] [Val...

EF6 Retrying procedure throws "The SqlParameter is already contained by another SqlParameterCollection" for SqlQuery command

I'm trying to use the DBExecutionStrategy to retry queries that have timed out, but when the time out happens I get the error "The SqlParameter is already contained by another SqlParameterCollection". I'm using EF6....My Query:...using (var ctx = new Enti...

Stored procedure in Entity Framework Core "enumeration yielded no results" error

In my ASP.NET Core 1.1 project with EF Core 1.1, I'm trying to call a SQL Server stored procedure by following this ...official MSDN article... and ...this post.... But I'm getting the above error inside the ...While loop... in the following code....I've ...

Entity Framework relation not loaded from database

I'm playing around with Entity Framework 6 Code First and have the problem that a many-to-many relationship is not correctly synchronized to my "internal" objects....I got following classes:...public class ClassA { public String AId { get; set; } ...

How to create a DBContext as part of an existing transaction in Entity Framework Core

I have product that already uses ADO.Net to access SQL Server and I'm using Entity Framework Core for some new functionality. The problem I'm having is I have some operations that must be done in a single transaction and the first few actions are implemen...

User defined table in Entity Framework generating incorrect query

I Think I am currently experiencing a bug in Entity Framework 6 and possibly ADO.NET. Since there is a deadline I am not sure I can wait for this bug to be fixed and hopefully someone can help me with a clean work around....The problem is that the query u...

C# .NET Core EF or ADO.NET query takes minutes and SSMS just 30 seconds, why?

So yeah, I'm currently stuck on a simple code that my app should do pretty quickly, considering the same query runs in SSMS in about 34 seconds and uses around 90mbps:...But then, look at what EF does while running the same query:...Not even using ADO.NET...

Is OR/M available in .NET core web API project?

In ASP.NET Framework projects one could right click the project and add a ADO.NET Entity Data Model using an existing database. This would create classes and properties from database's tables and columns. ...But this option is missing from ASP.NET Core AP...

How to dynamically select the DbSet column name?

I have the following ...DbContext... and entity (.Net core 3.11 console program)....public partial class MyDbContext : DbContext { private readonly string _connectionString; public MyDbContext(string connectionString) => _connectionString = conne...