The SCA$QUERY_SELECT_OCCURRENCE routine creates a query expression
    that matches a specific entity.

    You use this routine to specify queries based on the results
    of previous queries. The entity_handle parameter is obtained by
    traversing the results of a previous query evaluation.

    Typically, the query context of the entity_handle parameter is
    not the same as the query_context parameter. However, they can be
    the same. If they are the same query context, then that previous
    query is replaced with the query defined by this routine and, as a
    result, entity_handle becomes invalid.

    This routine will become obsolete in a future version of SCA. The
    SCA$SELECT_OCCURRENCE routine supersedes this routine.