Play with db constraints

bookshop/db/schema.cds

@@ -1,29 +1,19 @@
 using { Currency, managed, sap } from '@sap/cds/common';
 namespace sap.capire.bookshop;
 
-entity Books : managed {
+entity Books {
   key ID : Integer;
   title  : localized String(111);
-  descr  : localized String(1111);
   author : Association to Authors;
   genre  : Association to Genres;
-  stock  : Integer;
-  price  : Decimal;
-  currency : Currency;
-  image : LargeBinary @Core.MediaType : 'image/png';
 }
 
-entity Authors : managed {
+entity Authors {
   key ID : Integer;
   name   : String(111);
-  dateOfBirth  : Date;
-  dateOfDeath  : Date;
-  placeOfBirth : String;
-  placeOfDeath : String;
   books  : Association to many Books on books.author = $self;
 }
 
-/** Hierarchically organized Code List for Genres */
 entity Genres : sap.common.CodeList {
   key ID   : Integer;
   parent   : Association to Genres;