Entity Framework Core - Knowledge Base (KB)

Two (almost) concurrent DbContexts causing problems: How to share between Controller and AuthorizeAttribute

Every once in a while, I'm encountering the following exception in my ASP.NET/MVC5/WebAPI2/EF6/MSSQL application:...System.InvalidOperationException: The context cannot be used while the model is being created. This exception may be thrown if the context ...

DbUpdateConcurrencyException using Entity Framework 6 with MySql

I'm having trouble with concurrency checks using EF6 and MySQL....The problem I'm having is that I get a concurrency exception thrown when I try to save data to the database. If you examine the sql that is output to the console it tries to query the conc...

dbUpdateConcurrencyException on simple delete after loading

I've read several questions and articles about things that can cause a ...dbUpdateConcurrencyException... and none of them seem to be related to what's happening in my code. I have simple functional tests for my CRUD operations, which are using ...Entity ...

How to use EF Core concurrency token created by ForNpgsqlUseXminAsConcurrencyToken

I have found npgsql provider ...extension... to set up concurrency token for entity framework core entity, which should do something like this:...modelBuilder.Entity<MyEntity>(b => { b.Property<uint>("xmin") .HasColumnType("xid") .Valu...

Entity Framework Core RowVersion column not updating using PostgreSQL

I've set a RowVersion column for my entity but it seems that it isn't storing anything on creates or updates....it have this configuration in the DbContext ...OnModelCreating...:... modelBuilder.Entity<Author>() .Property(a => a.RowVersion) .IsCon...

Hangfire, .Net Core and Entity Framework: concurrency exception

I am developing a .Net core application with Hangfire and facing the below exception...A second operation started on this context before a previous operation completed. Any instance members are not guaranteed to be thread safe....I have used Hangfire for ...

Resolve an issue for Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException

I have an issue during an insert operation into the table using Entity Framework Core...._context.Entry(item).State = EntityState.Added; var r = await _context.ServiceWorkOrders.AddAsync(item); _context.SaveChangesAsync(); <-- (fails) ...Some context when...

Entity Framework concurrency with datetime field

I have an issue when I update an entity of my model:...var intervenant = this.IntervenantRepository.GetAll().FirstOrDefault(intervenant => intervenant.Id == intervenantId); if (IsInscrire) { intervenant.MotifdesinscId = null; intervenant.IsIn...