Filtering a Bundle by Resource.Effective

[AngeloMSFerreira]

Hello everyone!

I have been trying to perform a resource filtering by the 'Effective' attribute, but I seem to be running around in circles for the past hours and I am wondering if someone could give me a hand with this. The filtering method we have been using is the 'Select('query'), as shown below. (res is of type Bundle)

This works:
var selectedResource = res.Select("entry.resource.where(id = '" + resourceId + "')").FirstOrDefault();

This works:
var filteredResources = res.Select("entry.resource.ofType(" + resourceType + ")");

This doesn't work: (execute the below code on the QuickWatch)
Attempt 1
Description - Trying to compare with '2016-01-01' which is interpreted as string
res.Select("entry.resource.where(effective>='2016-01-01')"), results
"Invocation of operator '>=' failed: Cannot compare 2016-08-31T06:57:24-04:00 (of type Hl7.Fhir.ElementModel.Types.DateTime) to 2016-01-01 (of type Hl7.Fhir.ElementModel.Types.String), because the types differ."

Attempt 2
Description - Kept the quotes ( ' ' ) but changed the value inside to an actual DateTime initialization
res.Select("entry.resource.where(effective>='"+new DateTime(2016,1,1)+"')"), results
"Invocation of operator '>=' failed: Cannot compare 2016-08-31T06:57:24-04:00 (of type Hl7.Fhir.ElementModel.Types.DateTime) to 01/01/2016 00:00:00 (of type Hl7.Fhir.ElementModel.Types.String), because the types differ."

Attempt 3
Description - Previous one but without the quotes ( ' ' ) - Expected to be considered as string
res.Select("entry.resource.where(effective>="+new DateTime(2016,1,1)+")")
"Compilation failed: Parsing failure: unexpected '('; expected end of input (Line 1, Column 21); recently consumed: urce.where"

Does anyone have an idea on how to get this date comparison to work?

Thanks in advance!

Kind regards,
AF

[marcovisserFurore]

Hi @AngeloMSFerreira,

DateTime literals begin with a @. See also the FhirPath specification: http:https://hl7.org/fhirpath/#datetime

So try to write te expression like this:

  res.Select("entry.resource.where(effective >= @2016-01-01)");

Happy coding!

[AngeloMSFerreira]

Thank you Marco, this actually solved it!