What does it do? Field of a data source entity of the current CDS view entity. field expects the actual name of the element. Any alternative element names defined using AS cannot be used, with the exception of the ON condition of a CDS association. If the view entity makes use of multiple data sources by using join expressions, then all fields must be prefixed with the name of their data source separated by a period (.). The prefix is required in all cases, even if the field names are unique. For fields that are included via associations, special rules apply. See topic CDS DDL - CDS View Entity, path_expr.
