FIELDVALUE function
The FIELDVALUE field function returns the scalar value of a given field.
Syntax
FIELDVALUE returns the scalar value of the field identified by source_field_reference. If it identifies a non-existent field, NULL is returned.
For example, consider the following XML
input message:
<Data>
<Qty Unit="Gallons">1234</Qty>
</Data>
The ESQL statement SET OutputRoot.XML.Data.Quantity =
FIELDVALUE(InputRoot.XML.Data.Qty);
gives the result: <Data><Quantity>1234</Quantity></Data>
whereas
this ESQL statement (without the FIELDVALUE function): SET OutputRoot.XML.Data.Quantity =
InputRoot.XML.Data.Qty;
causes a tree copy, with the result: <Data><Quantity Unit="Gallons">1234</Quantity></Data>
because the field Qty
is not a leaf field.