initial upload of extension sample

db/extension.cds

@@ -0,0 +1,49 @@
+
+using {sap.capire.bookshop} from '_base/db/schema';
+using {sap.capire.orders} from '_base/db/schema';
+using from '_base/db/capire_common';
+
+using {
+    cuid, managed, Country
+} from '@sap/cds/common';
+
+namespace sap.bookshop.extension;
+
+extend orders.Orders with { 
+  Customer : Association to one Customers; 
+  Remarks  : Composition of many Remarks on Remarks.parent = $self;
+  priority : String @assert.range enum {high; medium; low} default 'medium';
+}  
+
+entity Customers : cuid, managed {
+  email        : String;
+  firstName    : String;
+  lastName     : String; 
+  creditCardNo : String;
+  dateOfBirth  : Date;
+  status       : String   @assert.range enum {platinum; gold; silver; bronze} default 'bronze';
+  creditScore  : Decimal  @assert.range: [ 1.0, 100.0 ] default 50.0;
+  PostalAddresses : Composition of many CustomerPostalAddresses on PostalAddresses.Customer = $self;
+}
+
+// new unique constraint (secondary index)
+annotate Customers with @assert.unique: { email: [ email ] }   
+{
+   email @mandatory;    // mandatory check
+}
+
+entity CustomerPostalAddresses : cuid, managed {
+  Customer       : Association to one Customers;
+  description    : String;
+  street         : String;
+  town           : String;
+  country        : Country;
+};
+
+entity Remarks : cuid, managed
+{  
+  parent      : Association to one orders.Orders;  
+  number      : Integer;
+  remarksLine : String; 
+}
+