What does it do? Field of a data source entity of the current ABAP_CDS_V1_VIEW . 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 you must ensure that all field names are unique. If a field name field is not unique, then field must be prefixed with the name entity of the data source or with the alias name alias of the data source separated by a period (.). If the field name is unique, it may but does not need to be prefixed.
