I had FHIR resource (https://www.hl7.org/fhir/) saved as XML in a SQL server database. After bit of a struggle found the way to extract data from XML, eg Given below to extract the FHIR resource status,
;WITH XMLNAMESPACES ('http://hl7.org/fhir' as X) select XMLDataColumn.value('(/X:FHIR_RESOURCE/X:status/@value)[1]', 'nvarchar(max)') as FHIR_Resource_Status
from FHIR_Resource_Table
Buminda 