REST API PUT requests suddenly return mostly "Sequence contains more than one matching element"

We’re using a custom endpoint.

​@joegrist Have you made any changes to the endpoint recently?

One of the things that I frequently see is when people map a field from details/grid to the header of the endpoint entity. That causes the system to select multiple records (because it joins the details).

This error is caused by the system having trouble locating the entity to be operated on.  It's something to do with the endpoint setup I suppose.  

It magically went away, but is now happening again.

I’m going to try deleting and re-creating the endpoint.

Here is the stack trace in a newer version of Acumatica, reading it carefully indicates the system is getting duplicates while trying to locate the entity to update,

{
    "message": "An error has occurred.",
    "exceptionMessage": "Sequence contains more than one matching element",
    "exceptionType": "System.InvalidOperationException",
    "stackTrace": "   at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable`1 source, Func`2 predicate)\r\n   at PX.Api.ContractBased.EntityExportContextBuilder.GetDescriptorKeys(EntityImpl entity, String baseMappingKey, Boolean includeNulls)\r\n   at PX.Api.ContractBased.EntityExportContextBuilder.TryDetermineDescriptorFromValues(EntityImpl entity, String baseMappingKey, EntityDescriptor& entityDescriptor, Boolean includeNulls)\r\n   at PX.Api.ContractBased.EntityService.DetermineEntityDescriptor(ISystemContract systemContract, String version, String name, EntityImpl entity, EntityExportContextBuilder entityExportContextBuilder, EntityDescriptor& entityDescriptor, PXGraph graph, CbOperationContext operationContext, Boolean& isArchived)\r\n   at PX.Api.ContractBased.EntityService.Put(ISystemContract systemContract, String version, String name, EntityImpl entity, CbOperationContext operationContext, Boolean throwOnError)\r\n   at PX.Api.ContractBased.AspNetCore.CbEndpointFeatureServiceExtensions.Put(IEntityService entityService, ICbEndpointFeature feature, EntityImpl entity, CbOperationContext operationContext)\r\n   at PX.Api.ContractBased.WebApi.Controllers.EntityController.PutEntity(EntityImpl entity, String select, String filter, String expand, String custom)\r\n   at lambda_method(Closure , Object , Object[] )\r\n   at Microsoft.AspNetCore.Mvc.Internal.ActionMethodExecutor.SyncActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)\r\n   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeActionMethodAsync>d__12.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeNextActionFilterAsync>d__10.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext context)\r\n   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)\r\n   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeInnerFilterAsync>d__13.MoveNext()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()\r\n   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.<InvokeNextExceptionFilterAsync>d__24.MoveNext()"
}

​@joegrist Do you have fields from ‘Details’ mapped to the header of the record in your endpoint?

​@Dmitrii Naumov no, thad doesn’t seem to be the issue here.  Here is the XML, I can’t see anything about this that isn’t completely boring and normal….

            <TopLevelEntity name="Appointment" screen="FS300200">
                <Fields>
                    <Field name="ActualDuration" type="StringValue" />
                    <Field name="ActualEndDate" type="DateTimeValue" />
                    <Field name="ActualEndTime" type="DateTimeValue" />
                    <Field name="ActualHandleManually" type="BooleanValue" />
                    <Field name="ActualServiceDuration" type="StringValue" />
                    <Field name="ActualStartDate" type="DateTimeValue" />
                    <Field name="ActualStartTime" type="DateTimeValue" />
                    <Field name="AppointmentNbr" type="StringValue" />
                    <Field name="Customer" type="StringValue" />
                    <Field name="Description" type="StringValue" />
                    <Field name="Details" type="AppointmentDetails[]" />
                    <Field name="EstimatedServiceDuration" type="StringValue" />
                    <Field name="Finished" type="BooleanValue" />
                    <Field name="Logs" type="AppointmentLogs[]" />
                    <Field name="ScheduledDuration" type="StringValue" />
                    <Field name="ScheduledEndDate" type="DateTimeValue" />
                    <Field name="ScheduledEndTime" type="DateTimeValue" />
                    <Field name="ScheduledHandleManually" type="BooleanValue" />
                    <Field name="ScheduledStartDate" type="DateTimeValue" />
                    <Field name="ScheduledStartTime" type="DateTimeValue" />
                    <Field name="ServiceOrderNbr" type="StringValue" />
                    <Field name="ServiceOrderType" type="StringValue" />
                    <Field name="Status" type="StringValue" />
                </Fields>
                <Mappings>
                    <Mapping field="ActualDuration">
                        <To object="AppointmentSelected" field="ActualDuration" />
                    </Mapping>
                    <Mapping field="Details">
                        <Mapping field="ActualDuration">
                            <To object="AppointmentDetails" field="ActualDuration" />
                        </Mapping>
                        <Mapping field="LineRef">
                            <To object="AppointmentDetails" field="LineRef" />
                        </Mapping>
                        <Mapping field="StaffMemberID">
                            <To object="AppointmentDetails" field="StaffID" />
                        </Mapping>
                        <Mapping field="AppointmentNbr">
                            <To object="AppointmentDetails" field="RefNbr" />
                        </Mapping>
                        <Mapping field="Branch">
                            <To object="AppointmentDetails" field="BranchID" />
                        </Mapping>
                        <Mapping field="EstimatedDuration">
                            <To object="AppointmentDetails" field="EstimatedDuration" />
                        </Mapping>
                        <Mapping field="InventoryID">
                            <To object="AppointmentDetails" field="InventoryID" />
                        </Mapping>
                        <Mapping field="LineNbr">
                            <To object="AppointmentDetails" field="LineNbr" />
                        </Mapping>
                        <Mapping field="LineStatus">
                            <To object="AppointmentDetails" field="UIStatus" />
                        </Mapping>
                        <Mapping field="LineType">
                            <To object="AppointmentDetails" field="LineType" />
                        </Mapping>
                        <Mapping field="Location">
                            <To object="AppointmentDetails" field="SiteLocationID" />
                        </Mapping>
                    </Mapping>
                    <Mapping field="EstimatedServiceDuration">
                        <To object="AppointmentRecords" field="EstimatedDurationTotal" />
                    </Mapping>
                    <Mapping field="Finished">
                        <To object="AppointmentSelected" field="Finished" />
                    </Mapping>
                    <Mapping field="ActualHandleManually">
                        <To object="AppointmentSelected" field="HandleManuallyActualTime" />
                    </Mapping>
                    <Mapping field="ScheduledHandleManually">
                        <To object="AppointmentSelected" field="HandleManuallyScheduleTime" />
                    </Mapping>
                    <Mapping field="Logs">
                        <Mapping field="AddtoActualDuration">
                            <To object="LogRecords" field="TrackOnService" />
                        </Mapping>
                        <Mapping field="LaborItem">
                            <To object="LogRecords" field="LaborItemID" />
                        </Mapping>
                        <Mapping field="LineNbr">
                            <To object="LogRecords" field="LineNbr" />
                        </Mapping>
                        <Mapping field="LogLineStatus">
                            <To object="LogRecords" field="Status" />
                        </Mapping>
                        <Mapping field="LogLineRef">
                            <To object="LogRecords" field="LineRef" />
                        </Mapping>
                        <Mapping field="ManageTimeManually">
                            <To object="LogRecords" field="KeepDateTimes" />
                        </Mapping>
                        <Mapping field="ServiceOrderType">
                            <To object="LogRecords" field="DocType" />
                        </Mapping>
                        <Mapping field="StaffMember">
                            <To object="LogRecords" field="BAccountID" />
                        </Mapping>
                        <Mapping field="StartDate">
                            <To object="LogRecords" field="DateTimeBegin_Date" />
                        </Mapping>
                        <Mapping field="StartTime">
                            <To object="LogRecords" field="DateTimeBegin_Time" />
                        </Mapping>
                        <Mapping field="TrackTime">
                            <To object="LogRecords" field="TrackTime" />
                        </Mapping>
                        <Mapping field="AppointmentNbr">
                            <To object="LogRecords" field="DocRefNbr" />
                        </Mapping>
                        <Mapping field="Description">
                            <To object="LogRecords" field="Descr" />
                        </Mapping>
                        <Mapping field="DetailLineRef">
                            <To object="LogRecords" field="DetLineRef" />
                        </Mapping>
                        <Mapping field="Duration">
                            <To object="LogRecords" field="TimeDuration" />
                        </Mapping>
                        <Mapping field="EarningType">
                            <To object="LogRecords" field="EarningType" />
                        </Mapping>
                        <Mapping field="EndDate">
                            <To object="LogRecords" field="DateTimeEnd_Date" />
                        </Mapping>
                        <Mapping field="EndTime">
                            <To object="LogRecords" field="DateTimeEnd_Time" />
                        </Mapping>
                        <Mapping field="InventoryID">
                            <To object="LogRecords" field="FSAppointmentDet__InventoryID" />
                        </Mapping>
                    </Mapping>
                    <Mapping field="ScheduledDuration">
                        <To object="AppointmentSelected" field="ScheduledDuration" />
                    </Mapping>
                    <Mapping field="ScheduledEndDate">
                        <To object="AppointmentSelected" field="ScheduledDateTimeEnd_Date" />
                    </Mapping>
                    <Mapping field="ScheduledEndTime">
                        <To object="AppointmentSelected" field="ScheduledDateTimeEnd_Time" />
                    </Mapping>
                    <Mapping field="ScheduledStartDate">
                        <To object="AppointmentSelected" field="ScheduledDateTimeBegin_Date" />
                    </Mapping>
                    <Mapping field="ActualEndDate">
                        <To object="AppointmentSelected" field="ActualDateTimeEnd_Date" />
                    </Mapping>
                    <Mapping field="ScheduledStartTime">
                        <To object="AppointmentSelected" field="ScheduledDateTimeBegin_Time" />
                    </Mapping>
                    <Mapping field="ServiceOrderNbr">
                        <To object="AppointmentRecords" field="SORefNbr" />
                    </Mapping>
                    <Mapping field="ServiceOrderType">
                        <To object="AppointmentRecords" field="SrvOrdType" />
                    </Mapping>
                    <Mapping field="Status">
                        <To object="AppointmentRecords" field="Status" />
                    </Mapping>
                    <Mapping field="ActualEndTime">
                        <To object="AppointmentSelected" field="ActualDateTimeEnd_Time" />
                    </Mapping>
                    <Mapping field="ActualServiceDuration">
                        <To object="AppointmentRecords" field="SrvOrdType" />
                    </Mapping>
                    <Mapping field="ActualStartDate">
                        <To object="AppointmentSelected" field="ExecutionDate" />
                    </Mapping>
                    <Mapping field="ActualStartTime">
                        <To object="AppointmentSelected" field="ActualDateTimeBegin_Time" />
                    </Mapping>
                    <Mapping field="AppointmentNbr">
                        <To object="AppointmentRecords" field="RefNbr" />
                    </Mapping>
                    <Mapping field="Customer">
                        <To object="AppointmentRecords" field="CustomerID" />
                    </Mapping>
                    <Mapping field="Description">
                        <To object="AppointmentRecords" field="DocDesc" />
                    </Mapping>
                </Mappings>
                <Actions>
                    <Action name="Complete" mappedTo="CompleteAppointment" />
                    <Action name="Start" mappedTo="StartAppointment" />
                </Actions>
            </TopLevelEntity>

By the way, this is very similar to the default endpoint, thete’s just less fields.  The purpose is to try and get the amount of data down as processing a lot of appointments is reeeeeeaaalllyyyyy slooooowwwww 

​@joegrist indeed, the mapping looks ok. Does the same request work with the default endpoint?

By the way, you don’t need to have an endpoint with limited set of fields. You can specify which subset of fields to return using the default endpoint. You need to specify the fields you want in the $select parameter and the other fields will not be returned.

​@Dmitrii Naumov Yes indeed, the request seems to work just fine on the default endpoint.  I was getting subjectively faster results using a custom endpoint, my guess is that it’s doing less JOINs in the background.  But I don’t have proper statistics to prove that.  Would be nice to fix this, but the default endpoint is working for now…. however I’m concerned this will happen again, naturally 

​@joegrist please submit a support case for proper investigation. We’ll take a look.