Resolving concurrency conflicts #3977

• ABP Framework version: v5.3.3
• UI type: MVC /
• DB provider: EF Core
• Tiered (MVC) or Identity Server Separated (Angular): yes
• Exception message and stack trace: The database operation was expected to affect 1 row(s), but actually affected 0 row(s); data may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=527962 for information on understanding and handling optimistic concurrency exceptions. Volo.Abp.Data.AbpDbConcurrencyException: The database operation was expected to affect 1 row(s), but actually affected 0 row(s); data may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=527962 for information on understanding and handling optimistic concurrency exceptions. ---> Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException: The database operation was expected to affect 1 row(s), but actually affected 0 row(s); data may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=527962 for information on understanding and handling optimistic concurrency exceptions. at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ThrowAggregateUpdateConcurrencyException(Int32 commandIndex, Int32 expectedRowsAffected, Int32 rowsAffected) at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ConsumeResultSetWithoutPropagationAsync(Int32 commandIndex, RelationalDataReader reader, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.ConsumeAsync(RelationalDataReader reader, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList1 entriesToSave, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(StateManager stateManager, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func4 operation, Func4 verifySucceeded, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken) at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken) at Volo.Abp.EntityFrameworkCore.AbpDbContext1.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken) --- End of inner exception stack trace --- at Volo.Abp.EntityFrameworkCore.AbpDbContext1.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken) at Volo.Abp.Uow.UnitOfWork.SaveChangesAsync(CancellationToken cancellationToken) at Volo.Abp.Uow.UnitOfWork.CompleteAsync(CancellationToken cancellationToken) at Volo.Abp.AspNetCore.Mvc.Uow.AbpUowActionFilter.OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next) at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context) at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextExceptionFilterAsync>g__Awaited|26_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
• Steps to reproduce the issue:"

• Try to submit concurrent update to the database

There is a nice documentation and blog post on how to check concurrency (https://docs.abp.io/en/abp/latest/Concurrency-Check), but there is no example on how to resolve conflicts manually. I don't understand how we can access the "values" (values on db, submitted data etc) ​​in case of conflict.

The SaveChangesAsync() function throws AbpDbConcurrencyException not DbUpdateConcurrencyException

The AbpDbConcurrencyException class does not derive from the DbUpdateConcurrencyException class.

For this reason, I cannot access the Current/Original/Database values ​​of the entity. (https://learn.microsoft.com/en-us/ef/core/saving/concurrency#resolving-concurrency-conflicts)

Can you share an example about the resolving concurrency conflicts ? Existing framework documentation doesn't provide any info resolving concurrency.