Active null value
Specify HL7 subcomponents using another square-bracketed comma-separated list. If the component or subcomponent list has multiple comma-separated elements, then the other list cannot contain them.
HL7 uses double-quote characters to represent the active null value. This is a value that is present in the message but explicitly empty. When an active null (sub)component is retrieved, the resulting DAT object has TYPE null.
For example, assume the patient-name field has "
"
in its middle-initial component:
Input: grmfetch $grmIdHl7\ {0(0).PID(0).00041(0).[2]}
Output: datum11
Input: datget datum11 VALUE
Output:
Input: datget datum11 TYPE
Output: null
grmfetch errors when retrieving an illegal field path. For example, undefined segment names or field IDs. If the address is legal, but not represented in the GRM object or its parsed message, then grmfetch returns a DAT object with an empty value.