Allow NULL value in MapValue()

[VictorioBerra]

I have a process that may or may not send a value:

List<CarModel> carsToSync = GetCarsFromAPI();

var maybeElectricMotorType = Console.GetStringFromUserInput();

public class CarModel
{
    public string CarId { get; set; }
    public string ElectricMotorType { get; set; } = null;
    public DateTimeOffset InsertedOnDate { get; set; }
}

DapperPlusManager
    .Entity<CarModel>()
    .Table("Car")
    .Key(x => x.CarId)
    .MapValue(maybeElectricMotorType, nameof(CarModel.ElectricMotorType))
    .AutoMap()

using var connection = new SqlConnection(connectionString);

connection.BulkSynchronize(carsToSync);

If maybeElectricMotorType is null, this will fail with an error from the mapper.

An alternative is to save a reference to DapperPlusEntityTypeMapper:

var dapperPlusEntityTypeMapper = DapperPlusManager
    .Entity<CarModel>()
    .Table("Car")
    .Key(x => x.CarId)
    .AutoMap()

if(maybeElectricMotorType is not null)
{
    dapperPlusEntityTypeMapper.MapValue(maybeElectricMotorType, nameof(CarModel.ElectricMotorType));
}

But I think this could be simpler by allowing nulls, or ignoring the MapValue if the value is null.

[JonathanMagnan]

Hello @VictorioBerra ,

Thank you for reporting, we will look at it.

I will assign it to my developer to better understand why the null value causes an exception.

Best Regards,

Jon

[JonathanMagnan]

Hello @VictorioBerra ,

The v4.0.26 has been released.

Let me know if we fixed correctly the issue when the value is null.

Best Regards,

Jon

[VictorioBerra]

Thanks for the quick turnaround, I appear to have the same issue:

System.Exception: An error occured while resolving the source name mapping of one of your columns.
   at Z.BulkOperations.BulkOperation.()
   at Z.BulkOperations.BulkOperation.Execute()
   at Z.BulkOperations.BulkOperation.BulkSynchronize()
   at Z.Dapper.Plus.DapperPlusAction.Execute()
   at Z.Dapper.Plus.DapperPlusActionSet`1.DapperPlusActionSetBuilder(DapperPlusContext context, IDbConnection connection, IDbTransaction transaction, String mapperKey, DapperPlusActionKind actionKind, IEnumerable`1 items, Func`2[] selectors)
   at Z.Dapper.Plus.DapperPlusActionSet`1..ctor(DapperPlusContext context, IDbTransaction transaction, String mapperKey, DapperPlusActionKind actionKind, IEnumerable`1 items, Func`2[] selectors)
   at Z.Dapper.Plus.DapperPlusExtensions.BulkSynchronize[T](IDbTransaction transaction, String mapperKey, IEnumerable`1 items, Func`2[] selectors)
   at Z.Dapper.Plus.DapperPlusExtensions.BulkSynchronize[T](IDbTransaction transaction, IEnumerable`1 items, Func`2[] selectors)
   at SalesForceDataLoad.Activities.BulkMergeActivity.OnExecuteAsync(ActivityExecutionContext context) in C:\Source\myapp.cs:line 89
   at Elsa.Services.Workflows.WorkflowRunner.TryExecuteActivityAsync(ActivityOperation activityOperation, ActivityExecutionContext activityExecutionContext, IActivity activity, CancellationToken cancellationToken)

It works if I go back to only applying the MapValue when its not null.

Just to clarify a few things, I am using a DateTimeOffset? property (instead of a string from my example), which I am mapping to a nullable DATETIMEOFFSET SQL Server column. I would imagine this does not matter, but I figured id mention it if it helps with testing.

[JonathanMagnan]

Hello @VictorioBerra ,

Thank you for reporting.

I will ask my developer to try with your column type. We sure indeed fixed something with the null value but perharp that was different of your issue.

[JonathanMagnan]

Hello @VictorioBerra ,

My developer tried unsuccessfully to reproduce the issue with the latest version

You can check his test online here: https://dotnetfiddle.net/Tzxgaa

Do you think you could create a runnable project with the issue? It doesn’t need to be your project, just a new solution with the minimum code to reproduce the issue. You can send it in private here: info@zzzprojects.com

Best Regards,

Jon

[VictorioBerra]

@JonathanMagnan Visual Studio did not correctly bump Z.Dapper.Plus to the fixed version, I re-tested and everything seems to be working great! I will close this. Thank you for the fix.