Entity Framework 6 - Knowledge Base (KB)

How do I construct a DbContext from an ObjectContext?

I am trying to create a constructor for my Context class from an ObjectContext. I want to do this because I am using DevExpress xaf which makes it easy to get hold of the ObjectContext from inside a view....The MSDN help is ...here... but it does not inc...

Could not load file or assembly: The located assembly's manifest definition does not match the assembly reference

I have a Dev Express web application working fine in localhost but not on the live site....I have logged the issue with Dev Express but am also logging it here because it may be a .net issue....I have checked the references carefully in the project and ca...

Which tables should have a timestamp column? Concurrency check with Entity Framework, XAF, DDD

I am using Dev Express XAF WinForms to write an ERP system....In practice I have found that my DBContext needs to have a DBSet for most of my business objects....I am trying to figure out which tables should have a timestamp column for optimistic concurre...

EntityFramework.SqlServer missing in release mode

I have several modules in my XAF Winforms application. The lowest tier makes use of Entity Framework 6.2 as installed by Nuget....The app runs fine in debug mode....However in release mode I get the following warning building. ...Severity Code Descr...

How do I get UWP Uninstall to remove database completely?

I have managed to get an XAF application into the Windows Store via the Desktop Bridge....When a user installs my software from the Windows Store and then chooses to uninstall, I want them to have the option to completely uninstall the software including...

Why would both sides of an if statement appear to execute?

I found a scenario where both sides of an if statement execute. Why?...I did not think that this was possible in C#....The problem occurs the second time I run an XAF EF Code First solution. After I have deleted the .mdf and _log.ldf files originally crea...

Why can't I see a localdb database created by a UWP (Desktop Bridge App) in the SQL Server Object Explorer?

Does UWP support LocalDB?... My investigations indicate there are some issues using localdb that I don't experience with SQL Server 2017 Development edition....I managed to convert a winforms EF-Code First, xaf application to run as a UWP app ...with the ...

SQL logic error no such table: porting xaf standard security to Sqlite

I am trying to make an XAF Winforms project run with SQLite. I am using Entity Framework 6 Code First with Standard Security....When I run the project I get...SQL logic error no such table: PermissionPolicyUsers at System.Data.SQLite.SQLite3.Prepare(S...

Multiplicity constraint violated (In XAF When createdObject.ObjectSpace.ModifiedObjects.Count has not been accessed.)

Question Summary:...Why would a "Multiplicity constraint violated" be able to be worked around by the introduction of the following line of code?...var numModifiedObjects =createdObject.ObjectSpace.ModifiedObjects.Count; ...Is there a setting that would ...

XAF Look up property displays correctly in listview but is null in detailview

I have the following business classes ( simplified )...public class Customer { Customer() { } public int Id {get;set;} public string Name {get;set;} public virtual Category {get;set;} } Public Class Category { public int Id {get;set;} p...

Change in sql server location causes Event 1026 .Net Runtime

I am connecting an application to a different SQL Server database and find the following error in the windows event log...The only change is the database server ...Event 1026, .NET Runtime...Application: My.MyApp2.Win.exe Framework Version: v4.0.30319 Des...