<das:field> element contains the name of a field in a data source record. Depending on the data source, a field may represent a column name
(in a table or SQL query in databases), or an attribute name (in XML files).
Attributes:
id - unique identifier of this resource in the current processing job.
name - the name of the field.
<das:field id="fld1" name="ID"/>
In XML data sources, a text node has a predefined name text().
<das:field id="fld2" name="text()"/>