Select from, string match

This operator is used implicitly to create a list of items from which to make a selection when using the special Query Type String match, lookup when used with pre-configured queries.

Self-selecting Property

It is also useful in the case where you have a Variable that is used at different levels of the taxonomic hierarchy to provide an increasingly detailed specification of its values. A common example of this for archaeology is the use of a Material variable which refines its list of sub-materials down successive levels of a hierarchy as needed (e.g. Stone, Basalt, Vesicular basalt). A common example of this for textual studies is the use of a Part of speech variable which list increasingly more specific parts of speech (e.g. Noun, Proper noun, Personal name) for grammatical tagging.

The select from operator is useful in a case such as this when used in a pre-configured query. The given Variable is set to select from its own Values as defined by its taxonomic contexts. Here for example the Materialvariable is set to select from itself.

This query is displayed in the View with a Select button that provides the hierarchy of Value options defined by the Material Variable.