From efc5b9f400a1dd2ca8928f21b395ccc9de7a51ca Mon Sep 17 00:00:00 2001
From: Daniel Hutzel <daniel.hutzel@sap.com>
Date: Wed, 20 Aug 2025 07:57:27 +0200
Subject: [PATCH 1/7] Experiments for dynamic constraints

---
 bookshop                                      |  2 +-
 bookstore                                     |  2 +-
 common                                        |  2 +-
 orders                                        |  2 +-
 reviews                                       |  2 +-
 shared-db                                     |  2 +-
 support                                       |  2 +-
 tests/dynamic-constraints/readme.md           | 30 +++++++
 tests/dynamic-constraints/server.js           | 17 ++++
 .../dynamic-constraints/srv/admin-service.cds | 14 ++++
 .../srv/etc/validation-aspects.cds            | 36 +++++++++
 .../dynamic-constraints/srv/field-control.cds | 10 +++
 tests/dynamic-constraints/srv/validation.cds  | 80 +++++++++++++++++++
 tests/dynamic-constraints/validate.js         | 34 ++++++++
 14 files changed, 228 insertions(+), 7 deletions(-)
 create mode 100644 tests/dynamic-constraints/readme.md
 create mode 100644 tests/dynamic-constraints/server.js
 create mode 100644 tests/dynamic-constraints/srv/admin-service.cds
 create mode 100644 tests/dynamic-constraints/srv/etc/validation-aspects.cds
 create mode 100644 tests/dynamic-constraints/srv/field-control.cds
 create mode 100644 tests/dynamic-constraints/srv/validation.cds
 create mode 100644 tests/dynamic-constraints/validate.js

diff --git a/bookshop b/bookshop
index b63c702..b97669d 160000
--- a/bookshop
+++ b/bookshop
@@ -1 +1 @@
-Subproject commit b63c7026912924b1e3b80550f1f5545efc22d93b
+Subproject commit b97669df334a4013a1302636ea12a931415eb61b
diff --git a/bookstore b/bookstore
index aeecd4c..05a9e65 160000
--- a/bookstore
+++ b/bookstore
@@ -1 +1 @@
-Subproject commit aeecd4c85582f49064d19c5195fab91376fdde0c
+Subproject commit 05a9e65870c317d4cc7c87964052b306fd9b5e19
diff --git a/common b/common
index 6fe89fb..56a29d5 160000
--- a/common
+++ b/common
@@ -1 +1 @@
-Subproject commit 6fe89fb51a6b06cf65d18f6d66ef880545a9054f
+Subproject commit 56a29d5370271f99b7aace6d562ab868193b792e
diff --git a/orders b/orders
index 726431b..9cfe5d5 160000
--- a/orders
+++ b/orders
@@ -1 +1 @@
-Subproject commit 726431bf3788d335b011b57914270b9c8770fd79
+Subproject commit 9cfe5d50b0b24840f2b5349d4c862ff03fd84c58
diff --git a/reviews b/reviews
index 9a8a608..f2d1db2 160000
--- a/reviews
+++ b/reviews
@@ -1 +1 @@
-Subproject commit 9a8a608a4005b41d45e1169951c89ec08e2abe0b
+Subproject commit f2d1db225e54438d6055f5d8bfefeeb02aa73f3b
diff --git a/shared-db b/shared-db
index a8ea11b..c5c923b 160000
--- a/shared-db
+++ b/shared-db
@@ -1 +1 @@
-Subproject commit a8ea11b774d1a453d5b85cb9959f479fcc804c53
+Subproject commit c5c923b23ce9d93455343c02fe236f7b2b904327
diff --git a/support b/support
index f325340..23b495f 160000
--- a/support
+++ b/support
@@ -1 +1 @@
-Subproject commit f32534054ff4e30c977c6dbef6785ca3d296a62f
+Subproject commit 23b495f94c41663c49b1da1e4598c3d1eedbc2f5
diff --git a/tests/dynamic-constraints/readme.md b/tests/dynamic-constraints/readme.md
new file mode 100644
index 0000000..4f27918
--- /dev/null
+++ b/tests/dynamic-constraints/readme.md
@@ -0,0 +1,30 @@
+## Experimental Dynamic Constraints
+
+This example demonstrates how to use dynamic constraints in a CAP application. It includes a service definition and a test setup to validate the constraints.
+
+
+### Prerequisites
+
+You've setup the [_cap/samples_](https://github.com/sap-samples/cloud-cap-samples) like so:
+
+```sh
+git clone -q https://github.com/capire/samples cap/samples
+cd cap/samples
+npm install
+```
+
+### Testing
+
+Test like that in `cds.repl` from _cap/samples_ root:
+
+```sh
+cds repl --run tests/dynamic-constraints
+````
+
+```javascript
+await AdminService.create ('Books', {})
+await AdminService.create ('Books', { title:'   ', author_ID:150 })
+await AdminService.create ('Books', { title:'x' })
+await cds.validate (Books.constraints, 201)
+await cds.validate (Books.constraints)
+```
diff --git a/tests/dynamic-constraints/server.js b/tests/dynamic-constraints/server.js
new file mode 100644
index 0000000..a2c7d7b
--- /dev/null
+++ b/tests/dynamic-constraints/server.js
@@ -0,0 +1,17 @@
+//
+// Quick and dirty implementation for cds.validate()
+// using db-level constraints.
+//
+
+const cds = require('@sap/cds'); require('./validate.js')
+cds.on('served', ()=> {
+  const { AdminService } = cds.services
+  AdminService.after (['CREATE','UPDATE'], (result,req) =>  cds.validate (req.subject, result))
+})
+
+
+
+Object.defineProperties (cds.entity.prototype, {
+  constraints: { get() { return cds.model.definitions[this.name+'.constraints'] }},
+  controls: { get() { return cds.model.definitions[this.name+'.field.control'] }},
+})
diff --git a/tests/dynamic-constraints/srv/admin-service.cds b/tests/dynamic-constraints/srv/admin-service.cds
new file mode 100644
index 0000000..a30130b
--- /dev/null
+++ b/tests/dynamic-constraints/srv/admin-service.cds
@@ -0,0 +1,14 @@
+using { AdminService } from '@capire/bookshop';
+namespace AdminService; //> for cds.entities
+
+annotate AdminService with @odata.draft.enabled;
+annotate AdminService with @requires: false;
+
+extend AdminService.Authors with columns {
+  null as books // to simulate the exclusion of books
+}
+
+// Should be provided by CAP ootb:
+extend AdminService.Books with columns {
+  active : Association to AdminService.Books on active.ID = $self.ID,
+}
diff --git a/tests/dynamic-constraints/srv/etc/validation-aspects.cds b/tests/dynamic-constraints/srv/etc/validation-aspects.cds
new file mode 100644
index 0000000..5b93d5d
--- /dev/null
+++ b/tests/dynamic-constraints/srv/etc/validation-aspects.cds
@@ -0,0 +1,36 @@
+using { sap.capire.bookshop.Books } from '@capire/bookshop';
+
+
+/**
+ * Validation constraints for Books
+ */
+@validations aspect AdminService.Books.constraints.aspect : Books {
+
+  // two-step mandatory check
+  check_title = case
+    when title is null  then 'is missing'
+    when trim(title)='' then 'must not be empty'
+  end;
+
+  check_title2 = (
+    title is null ? 'is missing' :
+    trim(title)='' ? 'must not be empty' : null
+  );
+
+  // range check
+  check_stock = stock < 0 ? 'must not be negative' : null;
+
+  // range check
+  check_price = price < 0 ? 'must not be negative' : null;
+
+  // assert target check
+  // check_genre = genre is not null and not exists genre ? 'does not exist' : null;
+
+  // multiple constraints: mandatory + assert target + special
+  check_author = case
+    when author.ID is null then 'is missing' // FIXME: 1) // TODO: 2)
+    // when not exists author then 'Author does not exist: ' || author.ID
+    when count(author.books.ID) -1 > 1 then author.name || ' already wrote too many books' // TODO: 3)
+    when /* exists */ author.books[genre.name like '%Noire%'] then 'Author has written a Noire book'
+  end
+}
diff --git a/tests/dynamic-constraints/srv/field-control.cds b/tests/dynamic-constraints/srv/field-control.cds
new file mode 100644
index 0000000..3b48b7a
--- /dev/null
+++ b/tests/dynamic-constraints/srv/field-control.cds
@@ -0,0 +1,10 @@
+namespace sap.capire.bookshop;
+using from './admin-service';
+
+view Books.field.control as select from Books { ID,
+  genre.name == 'Drama' ? 'readonly' :
+  null as price
+}
+extend Books with {
+  fc : Association to Books.field.control on fc.ID = $self.ID
+}
diff --git a/tests/dynamic-constraints/srv/validation.cds b/tests/dynamic-constraints/srv/validation.cds
new file mode 100644
index 0000000..b3f340b
--- /dev/null
+++ b/tests/dynamic-constraints/srv/validation.cds
@@ -0,0 +1,80 @@
+using { AdminService, sap.capire.bookshop as my } from './admin-service';
+
+extend service AdminService with {
+
+  // entity Books.drafts as projection on AdminService.Books;
+  // @cds.api.ignore view Books.drafts.constraints as select from AdminService.Books.drafts mixin {
+  //   before: Association to my.Books on before.ID = $self.ID;
+  //   base: Association to my.Books on base.ID = $self.ID;
+  // } into { ID, // FIXME: compiler should resolve Books without AdminService prefix
+  //   case
+  //     when title is null  then 'is missing'
+  //     when trim(title)='' then 'must not be empty'
+  //   end as title,
+  //   ...
+  // }
+
+  /**
+   * Validation constraints for Books
+   */
+  @validation view Books.constraints as select from AdminService.Books mixin {
+    base: Association to my.Books on base.ID = $self.ID // Should be provided by CAP ootb
+  } into {
+    ID,
+
+    // two-step mandatory check
+    case
+      when title is null  then 'is missing'
+      when trim(title)='' then 'must not be empty'
+    end as title,
+    // the above is equivalent to:
+    // title is null ? 'is missing' : trim(title)='' ? 'must not be empty' :
+
+    // range check
+    stock < 0 ? 'must not be negative' :
+    null as stock,
+
+    // range check
+    price < 0 ? 'must not be negative' :
+    null as price,
+
+    // assert target check
+    genre.ID is not null and not exists genre ? 'does not exist' :
+    null as genre,
+
+    // multiple constraints: mandatory + assert target + special
+    author.ID is null ? 'is missing' : // FIXME: 1) // TODO: 2)
+    not exists author ? 'Author does not exist: ' || author.ID :
+    count(base.author.books.ID) -1 > 1 ? author.name || ' already wrote too many books' : // TODO: 3)
+    null as author,
+
+  } group by ID;
+
+  // 1) FIXME: expected author.ID to refer to foreign key,
+  // apparently that is not the case -> move one line up
+  // and run test to see the erroneous impact.
+
+  // 2) TODO: we should allow to write author is null instead of author.ID is null
+
+  // 3) TODO: we should support count(author.books)
+
+
+  /**
+   * Validation constraints for Authors
+   */
+  @validation view Authors.constraints as select from AdminService.Authors { ID, // FIXME: compiler should resolve Authors without AdminService prefix
+
+    // two-step mandatory check
+    name = null ? 'is missing' : trim(name)='' ? 'must not be empty' :
+    null as name,
+
+    // constraint related to two fields
+    dateOfDeath < dateOfBirth ? 'we can''t die before we are born' : null as _born_before_death,
+    $self._born_before_death as dateOfBirth,
+    $self._born_before_death as dateOfDeath,
+
+  }
+}
+
+
+annotate AdminService.Books.constraints with @cds.api.ignore @odata.draft.enabled: false;
diff --git a/tests/dynamic-constraints/validate.js b/tests/dynamic-constraints/validate.js
new file mode 100644
index 0000000..2290700
--- /dev/null
+++ b/tests/dynamic-constraints/validate.js
@@ -0,0 +1,34 @@
+const cds = require('@sap/cds')
+const $super = { validate: cds.validate, skip(){} }
+
+
+/**
+ * Quick and dirty implementation for cds.validate() using db-level constraints.
+ */
+cds.validate = function (x, pk, ...columns) {
+
+  // Delegate to base impl of cds.validate() for standard input validation
+  if (!_is_constraints(x)) return $super.skip (...arguments)
+
+  // Support subject refs to base entities as arguments
+  if (x?.ref) [ x, pk ] = [ x.ref +'.constraints', pk.ID||pk ]
+
+  // Run the constraints check query
+  const constraints = typeof x === 'string' ? cds.model.definitions[x] || cds.error `No such constraints view: ${x}` : x
+  return SELECT.from (constraints, pk, columns.length && columns)
+
+  // Collect and throw errors, if any
+  .then (rows => (rows.map ? rows : [rows]).map (checks => {
+    const failed = {}; for (let c in checks) {
+      if (c in constraints.keys) continue
+      if (c[0] == '_') continue
+      if (checks[c]) failed[c] = checks[c]
+    }
+    if (Object.keys(failed).length) throw cds.error `Invalid input: ${failed}`
+    return checks
+  }))
+}
+
+
+// Helpers
+const _is_constraints = x => x.ref || x.is_entity || typeof x === 'string'

From dde55a9d558b373f3a335fca42c89ac1557f4232 Mon Sep 17 00:00:00 2001
From: Daniel Hutzel <daniel.hutzel@sap.com>
Date: Wed, 20 Aug 2025 07:59:15 +0200
Subject: [PATCH 2/7] Adjusted branch

---
 tests/dynamic-constraints/readme.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/dynamic-constraints/readme.md b/tests/dynamic-constraints/readme.md
index 4f27918..cb7f2de 100644
--- a/tests/dynamic-constraints/readme.md
+++ b/tests/dynamic-constraints/readme.md
@@ -5,10 +5,10 @@ This example demonstrates how to use dynamic constraints in a CAP application. I
 
 ### Prerequisites
 
-You've setup the [_cap/samples_](https://github.com/sap-samples/cloud-cap-samples) like so:
+You've setup the [_cap/samples_](https://github.com/capire/samples) like so:
 
 ```sh
-git clone -q https://github.com/capire/samples cap/samples
+git clone -b dynamic-constraints -q https://github.com/capire/samples cap/samples
 cd cap/samples
 npm install
 ```

From d12dd76c182d2c299f57fa25839dcfabf22a0bd1 Mon Sep 17 00:00:00 2001
From: Daniel Hutzel <daniel.hutzel@sap.com>
Date: Wed, 20 Aug 2025 09:04:33 +0200
Subject: [PATCH 3/7] Showcase field control

---
 tests/dynamic-constraints/readme.md           |   9 +-
 .../dynamic-constraints/srv/field-control.cds |  11 +-
 tests/dynamic-constraints/srv/validation.cds  | 145 +++++++++---------
 3 files changed, 85 insertions(+), 80 deletions(-)

diff --git a/tests/dynamic-constraints/readme.md b/tests/dynamic-constraints/readme.md
index cb7f2de..baf76ad 100644
--- a/tests/dynamic-constraints/readme.md
+++ b/tests/dynamic-constraints/readme.md
@@ -21,10 +21,17 @@ Test like that in `cds.repl` from _cap/samples_ root:
 cds repl --run tests/dynamic-constraints
 ````
 
-```javascript
+```js
 await AdminService.create ('Books', {})
 await AdminService.create ('Books', { title:'   ', author_ID:150 })
 await AdminService.create ('Books', { title:'x' })
+```
+
+```js
 await cds.validate (Books.constraints, 201)
 await cds.validate (Books.constraints)
 ```
+
+```js
+await AdminService.read `ID, title, price, fc.price from Books`
+```
diff --git a/tests/dynamic-constraints/srv/field-control.cds b/tests/dynamic-constraints/srv/field-control.cds
index 3b48b7a..37d3af9 100644
--- a/tests/dynamic-constraints/srv/field-control.cds
+++ b/tests/dynamic-constraints/srv/field-control.cds
@@ -1,10 +1,11 @@
-namespace sap.capire.bookshop;
-using from './admin-service';
+using { AdminService } from './admin-service';
 
-view Books.field.control as select from Books { ID,
+@fieldcontrol view AdminService.Books.field.control as select from AdminService.Books { ID,
   genre.name == 'Drama' ? 'readonly' :
   null as price
 }
-extend Books with {
-  fc : Association to Books.field.control on fc.ID = $self.ID
+
+// Make that available to Fiori clients
+extend AdminService.Books with columns {
+  fc : Association to AdminService.Books.field.control on fc.ID = $self.ID
 }
diff --git a/tests/dynamic-constraints/srv/validation.cds b/tests/dynamic-constraints/srv/validation.cds
index b3f340b..cef8e47 100644
--- a/tests/dynamic-constraints/srv/validation.cds
+++ b/tests/dynamic-constraints/srv/validation.cds
@@ -1,79 +1,76 @@
 using { AdminService, sap.capire.bookshop as my } from './admin-service';
 
-extend service AdminService with {
-
-  // entity Books.drafts as projection on AdminService.Books;
-  // @cds.api.ignore view Books.drafts.constraints as select from AdminService.Books.drafts mixin {
-  //   before: Association to my.Books on before.ID = $self.ID;
-  //   base: Association to my.Books on base.ID = $self.ID;
-  // } into { ID, // FIXME: compiler should resolve Books without AdminService prefix
-  //   case
-  //     when title is null  then 'is missing'
-  //     when trim(title)='' then 'must not be empty'
-  //   end as title,
-  //   ...
-  // }
-
-  /**
-   * Validation constraints for Books
-   */
-  @validation view Books.constraints as select from AdminService.Books mixin {
-    base: Association to my.Books on base.ID = $self.ID // Should be provided by CAP ootb
-  } into {
-    ID,
-
-    // two-step mandatory check
-    case
-      when title is null  then 'is missing'
-      when trim(title)='' then 'must not be empty'
-    end as title,
-    // the above is equivalent to:
-    // title is null ? 'is missing' : trim(title)='' ? 'must not be empty' :
-
-    // range check
-    stock < 0 ? 'must not be negative' :
-    null as stock,
-
-    // range check
-    price < 0 ? 'must not be negative' :
-    null as price,
-
-    // assert target check
-    genre.ID is not null and not exists genre ? 'does not exist' :
-    null as genre,
-
-    // multiple constraints: mandatory + assert target + special
-    author.ID is null ? 'is missing' : // FIXME: 1) // TODO: 2)
-    not exists author ? 'Author does not exist: ' || author.ID :
-    count(base.author.books.ID) -1 > 1 ? author.name || ' already wrote too many books' : // TODO: 3)
-    null as author,
-
-  } group by ID;
-
-  // 1) FIXME: expected author.ID to refer to foreign key,
-  // apparently that is not the case -> move one line up
-  // and run test to see the erroneous impact.
-
-  // 2) TODO: we should allow to write author is null instead of author.ID is null
-
-  // 3) TODO: we should support count(author.books)
-
-
-  /**
-   * Validation constraints for Authors
-   */
-  @validation view Authors.constraints as select from AdminService.Authors { ID, // FIXME: compiler should resolve Authors without AdminService prefix
-
-    // two-step mandatory check
-    name = null ? 'is missing' : trim(name)='' ? 'must not be empty' :
-    null as name,
-
-    // constraint related to two fields
-    dateOfDeath < dateOfBirth ? 'we can''t die before we are born' : null as _born_before_death,
-    $self._born_before_death as dateOfBirth,
-    $self._born_before_death as dateOfDeath,
-
-  }
+// entity Books.drafts as projection on AdminService.Books;
+// @cds.api.ignore view Books.drafts.constraints as select from AdminService.Books.drafts mixin {
+//   before: Association to my.Books on before.ID = $self.ID;
+//   base: Association to my.Books on base.ID = $self.ID;
+// } into { ID, // FIXME: compiler should resolve Books without AdminService prefix
+//   case
+//     when title is null  then 'is missing'
+//     when trim(title)='' then 'must not be empty'
+//   end as title,
+//   ...
+// }
+
+/**
+ * Validation constraints for Books
+ */
+@validation view AdminService.Books.constraints as select from AdminService.Books mixin {
+  base: Association to my.Books on base.ID = $self.ID // Should be provided by CAP ootb
+} into {
+  ID,
+
+  // two-step mandatory check
+  case
+    when title is null  then 'is missing'
+    when trim(title)='' then 'must not be empty'
+  end as title,
+  // the above is equivalent to:
+  // title is null ? 'is missing' : trim(title)='' ? 'must not be empty' :
+
+  // range check
+  stock < 0 ? 'must not be negative' :
+  null as stock,
+
+  // range check
+  price < 0 ? 'must not be negative' :
+  null as price,
+
+  // assert target check
+  genre.ID is not null and not exists genre ? 'does not exist' :
+  null as genre,
+
+  // multiple constraints: mandatory + assert target + special
+  author.ID is null ? 'is missing' : // FIXME: 1) // TODO: 2)
+  not exists author ? 'Author does not exist: ' || author.ID :
+  count(base.author.books.ID) -1 > 1 ? author.name || ' already wrote too many books' : // TODO: 3)
+  null as author,
+
+} group by ID; // because of the count(base.author.books) above
+
+// 1) FIXME: expected author.ID to refer to foreign key,
+// apparently that is not the case -> move one line up
+// and run test to see the erroneous impact.
+
+// 2) TODO: we should allow to write author is null instead of author.ID is null
+
+// 3) TODO: we should support count(author.books)
+
+
+/**
+ * Validation constraints for Authors
+ */
+@validation view AdminService.Authors.constraints as select from AdminService.Authors { ID, // FIXME: compiler should resolve Authors without AdminService prefix
+
+  // two-step mandatory check
+  name = null ? 'is missing' : trim(name)='' ? 'must not be empty' :
+  null as name,
+
+  // constraint related to two fields
+  dateOfDeath < dateOfBirth ? 'we can''t die before we are born' : null as _born_before_death, // reuse condition
+  $self._born_before_death as dateOfBirth,
+  $self._born_before_death as dateOfDeath,
+
 }
 
 

From 49df06544b635669efbcd5b5ed0bd3cda8b15d48 Mon Sep 17 00:00:00 2001
From: Daniel Hutzel <daniel.hutzel@sap.com>
Date: Sun, 24 Aug 2025 14:45:56 +0200
Subject: [PATCH 4/7] ...

---
 .../dynamic-constraints/fts/some-feature.cds  |  5 ++
 tests/dynamic-constraints/server.js           |  2 +-
 .../dynamic-constraints/srv/admin-service.cds |  2 +-
 tests/dynamic-constraints/srv/etc/catalog.cds | 20 +++++
 .../srv/etc/requisition.cds                   | 31 +++++++
 .../srv/etc/some-body-else.cds                | 16 ++++
 .../srv/etc/validation-asserts.cds            | 47 +++++++++++
 .../srv/etc/validation-views.cds              | 80 +++++++++++++++++++
 tests/dynamic-constraints/srv/validation.cds  | 78 +-----------------
 tests/dynamic-constraints/validate.js         | 65 ++++++++++-----
 10 files changed, 249 insertions(+), 97 deletions(-)
 create mode 100644 tests/dynamic-constraints/fts/some-feature.cds
 create mode 100644 tests/dynamic-constraints/srv/etc/catalog.cds
 create mode 100644 tests/dynamic-constraints/srv/etc/requisition.cds
 create mode 100644 tests/dynamic-constraints/srv/etc/some-body-else.cds
 create mode 100644 tests/dynamic-constraints/srv/etc/validation-asserts.cds
 create mode 100644 tests/dynamic-constraints/srv/etc/validation-views.cds

diff --git a/tests/dynamic-constraints/fts/some-feature.cds b/tests/dynamic-constraints/fts/some-feature.cds
new file mode 100644
index 0000000..263f572
--- /dev/null
+++ b/tests/dynamic-constraints/fts/some-feature.cds
@@ -0,0 +1,5 @@
+using { sap.ariba.buying.Requisitions } from '../srv/etc/requisition';
+
+annotate Requisitions with {
+  buyer @assert: (buyer is null ? 'is missing' : null);
+}
diff --git a/tests/dynamic-constraints/server.js b/tests/dynamic-constraints/server.js
index a2c7d7b..c833857 100644
--- a/tests/dynamic-constraints/server.js
+++ b/tests/dynamic-constraints/server.js
@@ -6,7 +6,7 @@
 const cds = require('@sap/cds'); require('./validate.js')
 cds.on('served', ()=> {
   const { AdminService } = cds.services
-  AdminService.after (['CREATE','UPDATE'], (result,req) =>  cds.validate (req.subject, result))
+  AdminService.after (['CREATE','UPDATE'], (_,req) =>  cds.validate (req))
 })
 
 
diff --git a/tests/dynamic-constraints/srv/admin-service.cds b/tests/dynamic-constraints/srv/admin-service.cds
index a30130b..25b1460 100644
--- a/tests/dynamic-constraints/srv/admin-service.cds
+++ b/tests/dynamic-constraints/srv/admin-service.cds
@@ -5,7 +5,7 @@ annotate AdminService with @odata.draft.enabled;
 annotate AdminService with @requires: false;
 
 extend AdminService.Authors with columns {
-  null as books // to simulate the exclusion of books
+  // null as books // to simulate the exclusion of books
 }
 
 // Should be provided by CAP ootb:
diff --git a/tests/dynamic-constraints/srv/etc/catalog.cds b/tests/dynamic-constraints/srv/etc/catalog.cds
new file mode 100644
index 0000000..3a8cea2
--- /dev/null
+++ b/tests/dynamic-constraints/srv/etc/catalog.cds
@@ -0,0 +1,20 @@
+using { cuid, Currency } from '@sap/cds/common';
+
+context sap.ariba.catalog {
+
+  entity Product : cuid { // = ProductDescription in Ariba CG
+    name : String(111);
+    descr : String(1111);
+    price : Decimal(10,2);
+    stock : Integer;
+    suppliers : Association to many Suppliers;
+  }
+
+  entity Suppliers : cuid {
+    name : String(111);
+    contact : String(111);
+    address : String(1111);
+    currency : Currency;
+  }
+
+}
diff --git a/tests/dynamic-constraints/srv/etc/requisition.cds b/tests/dynamic-constraints/srv/etc/requisition.cds
new file mode 100644
index 0000000..30cb706
--- /dev/null
+++ b/tests/dynamic-constraints/srv/etc/requisition.cds
@@ -0,0 +1,31 @@
+
+using { cuid } from '@sap/cds/common';
+using { sap.ariba.catalog.Product, sap.ariba.catalog.Suppliers } from './catalog';
+
+type Price : Decimal(10,2);
+
+context sap.ariba.buying {
+
+  entity Requisitions : cuid {
+    buyer : String;
+    Items : Composition of many LineItems on Items.parent = $self;
+    totalPrice : Price;
+  }
+
+  entity LineItems {
+    key parent : Association to Requisitions;
+    key pos  : Integer;
+    product  : Association to Product;
+    supplier : Association to Suppliers; //
+    quantity : Integer;
+    // supplierCurrency : Currency;
+  };
+
+  // entity Product : sap.ariba.catalog.Product {
+  //   product : Association to Product;
+  // }
+  entity Suppliers : sap.ariba.catalog.Suppliers {
+    product : Association to Product;
+  }
+
+}
diff --git a/tests/dynamic-constraints/srv/etc/some-body-else.cds b/tests/dynamic-constraints/srv/etc/some-body-else.cds
new file mode 100644
index 0000000..6806745
--- /dev/null
+++ b/tests/dynamic-constraints/srv/etc/some-body-else.cds
@@ -0,0 +1,16 @@
+using { sap.ariba.buying } from './requisition';
+context other {
+
+  aspect managed {
+    createdBy: User @assert: (createdBy is not null ? null : 'is missing');
+    createdAt: DateTime;
+    lastModifiedBy: User;
+    lastModifiedAt: DateTime;
+  }
+
+  type User : String;
+
+  extend buying.Requisitions with managed;
+  extend buying.Suppliers with managed;
+
+}
diff --git a/tests/dynamic-constraints/srv/etc/validation-asserts.cds b/tests/dynamic-constraints/srv/etc/validation-asserts.cds
new file mode 100644
index 0000000..c03836e
--- /dev/null
+++ b/tests/dynamic-constraints/srv/etc/validation-asserts.cds
@@ -0,0 +1,47 @@
+using { sap.capire.bookshop.Books } from '@capire/bookshop';
+
+// Following are invariant constraints declared on domain model entity
+annotate Books with {
+
+  // manual two-step mandatory constraint
+  title @assert: (case
+    when title is null  then 'is missing'
+    when trim(title)='' then 'must not be empty'
+  end);
+
+  // range check
+  stock @assert: (case
+    when stock < 0 then 'must not be negative'
+  end);
+
+  // range check
+  price @assert: (case
+    when price <= 0 or price > 500 then 'must be between 0 and 500'
+   end);
+
+  // assert target check
+  genre @assert: (case
+    when genre is not null and not exists genre then 'does not exist'
+   end);
+
+  // multiple constraints: mandatory + assert target + special
+  author @assert: (case
+    when author is null then 'is missing'
+    when not exists author then 'does not exist'
+  end);
+}
+
+// Following need to go on service-level entity, as rewriting would fail for CatalogService
+annotate AdminService.Books with {
+
+  author @assert: (case
+    when sum(author.books.price) > 111 then author.name || ' already earned too much with his/her books'
+    when count(author.books.ID) -1 > 1 then author.name || ' already wrote too many books'
+    // FIXME: ^^^^^^^^^^^^^^^^ cqn4sql doesn't support count(author.books) yet
+  end);
+
+  price @assert: (case
+    when price is null and exists author.books.genre[name = 'Drama']
+    then 'Price must be specified for books by drama queens'
+  end);
+}
diff --git a/tests/dynamic-constraints/srv/etc/validation-views.cds b/tests/dynamic-constraints/srv/etc/validation-views.cds
new file mode 100644
index 0000000..b390cee
--- /dev/null
+++ b/tests/dynamic-constraints/srv/etc/validation-views.cds
@@ -0,0 +1,80 @@
+using { AdminService, sap.capire.bookshop as my } from '../admin-service';
+
+// entity Books.drafts as projection on AdminService.Books;
+// @cds.api.ignore view Books.drafts.constraints as select from AdminService.Books.drafts mixin {
+//   before: Association to my.Books on before.ID = $self.ID;
+//   base: Association to my.Books on base.ID = $self.ID;
+// } into { ID, // FIXME: compiler should resolve Books without AdminService prefix
+//   case
+//     when title is null  then 'is missing'
+//     when trim(title)='' then 'must not be empty'
+//   end as title,
+//   ...
+// }
+
+/**
+ * Validation constraints for Books
+ */
+@validation view AdminService.Books.constraints as select from AdminService.Books mixin {
+  base: Association to my.Books on base.ID = $self.ID // Should be provided by CAP ootb
+} into {
+  ID,
+
+  // two-step mandatory check
+  case
+    when title is null  then 'is missing'
+    when trim(title)='' then 'must not be empty'
+  end as title,
+  // the above is equivalent to:
+  // title is null ? 'is missing' : trim(title)='' ? 'must not be empty' :
+
+  // range check
+  stock < 0 ? 'must not be negative' :
+  null as stock,
+
+  // range check
+  price < 0 ? 'must not be negative' :
+  null as price,
+
+  // assert target check
+  genre.ID is not null and not exists genre ? 'does not exist' :
+  null as genre,
+
+  genre.name as _genre,
+
+  // multiple constraints: mandatory + assert target + special
+  case
+    when author.ID is null then 'is missing' // FIXME: 1) // TODO: 2)
+    when not exists author then 'Author does not exist: ' || author.ID
+    when sum(base.author.books.price) > 111 then author.name || ' already earned too much' // TODO: 3)
+  end as author,
+
+} group by ID; // because of the count(base.author.books) above
+
+// 1) FIXME: expected author.ID to refer to foreign key,
+// apparently that is not the case -> move one line up
+// and run test to see the erroneous impact.
+
+// 2) TODO: we should allow to write author is null instead of author.ID is null
+
+// 3) TODO: we should support count(author.books)
+
+
+/**
+ * Validation constraints for Authors
+ */
+@validation view AdminService.Authors.constraints as select from AdminService.Authors { ID, // FIXME: compiler should resolve Authors without AdminService prefix
+
+  // two-step mandatory check
+  name = null ? 'is missing' : trim(name)='' ? 'must not be empty' :
+  null as name,
+
+  // constraint related to two fields
+  dateOfDeath < dateOfBirth ? 'we can''t die before we are born' : null as _born_before_death, // reuse condition
+  $self._born_before_death as dateOfBirth,
+  $self._born_before_death as dateOfDeath,
+
+}
+
+
+annotate AdminService.Books.constraints with @cds.api.ignore @odata.draft.enabled: false;
diff --git a/tests/dynamic-constraints/srv/validation.cds b/tests/dynamic-constraints/srv/validation.cds
index cef8e47..be0b242 100644
--- a/tests/dynamic-constraints/srv/validation.cds
+++ b/tests/dynamic-constraints/srv/validation.cds
@@ -1,77 +1 @@
-using { AdminService, sap.capire.bookshop as my } from './admin-service';
-
-// entity Books.drafts as projection on AdminService.Books;
-// @cds.api.ignore view Books.drafts.constraints as select from AdminService.Books.drafts mixin {
-//   before: Association to my.Books on before.ID = $self.ID;
-//   base: Association to my.Books on base.ID = $self.ID;
-// } into { ID, // FIXME: compiler should resolve Books without AdminService prefix
-//   case
-//     when title is null  then 'is missing'
-//     when trim(title)='' then 'must not be empty'
-//   end as title,
-//   ...
-// }
-
-/**
- * Validation constraints for Books
- */
-@validation view AdminService.Books.constraints as select from AdminService.Books mixin {
-  base: Association to my.Books on base.ID = $self.ID // Should be provided by CAP ootb
-} into {
-  ID,
-
-  // two-step mandatory check
-  case
-    when title is null  then 'is missing'
-    when trim(title)='' then 'must not be empty'
-  end as title,
-  // the above is equivalent to:
-  // title is null ? 'is missing' : trim(title)='' ? 'must not be empty' :
-
-  // range check
-  stock < 0 ? 'must not be negative' :
-  null as stock,
-
-  // range check
-  price < 0 ? 'must not be negative' :
-  null as price,
-
-  // assert target check
-  genre.ID is not null and not exists genre ? 'does not exist' :
-  null as genre,
-
-  // multiple constraints: mandatory + assert target + special
-  author.ID is null ? 'is missing' : // FIXME: 1) // TODO: 2)
-  not exists author ? 'Author does not exist: ' || author.ID :
-  count(base.author.books.ID) -1 > 1 ? author.name || ' already wrote too many books' : // TODO: 3)
-  null as author,
-
-} group by ID; // because of the count(base.author.books) above
-
-// 1) FIXME: expected author.ID to refer to foreign key,
-// apparently that is not the case -> move one line up
-// and run test to see the erroneous impact.
-
-// 2) TODO: we should allow to write author is null instead of author.ID is null
-
-// 3) TODO: we should support count(author.books)
-
-
-/**
- * Validation constraints for Authors
- */
-@validation view AdminService.Authors.constraints as select from AdminService.Authors { ID, // FIXME: compiler should resolve Authors without AdminService prefix
-
-  // two-step mandatory check
-  name = null ? 'is missing' : trim(name)='' ? 'must not be empty' :
-  null as name,
-
-  // constraint related to two fields
-  dateOfDeath < dateOfBirth ? 'we can''t die before we are born' : null as _born_before_death, // reuse condition
-  $self._born_before_death as dateOfBirth,
-  $self._born_before_death as dateOfDeath,
-
-}
-
-
-annotate AdminService.Books.constraints with @cds.api.ignore @odata.draft.enabled: false;
+using from './etc/validation-asserts';
diff --git a/tests/dynamic-constraints/validate.js b/tests/dynamic-constraints/validate.js
index 2290700..4867dc4 100644
--- a/tests/dynamic-constraints/validate.js
+++ b/tests/dynamic-constraints/validate.js
@@ -5,30 +5,59 @@ const $super = { validate: cds.validate, skip(){} }
 /**
  * Quick and dirty implementation for cds.validate() using db-level constraints.
  */
-cds.validate = function (x, pk, ...columns) {
+cds.validate = function (req) {
+  if (req.is_entity) {
+    const asserts = _collect_asserts4 (req); if (!asserts.length) return
+    const vq = SELECT.from (req) .columns (asserts)
+    return vq .then (_handle_results)
+  }
+  if (req instanceof cds.Request === false) return // $super.validate (...arguments)
+  const vq = _validation_query4 (req)
+  return vq .then (_handle_results)
+}
 
-  // Delegate to base impl of cds.validate() for standard input validation
-  if (!_is_constraints(x)) return $super.skip (...arguments)
+function _validation_query4 (req) {
+  let pk = _key_from_data (req)
+  let constraints = cds.model.definitions [req.target.name + '.constraints']
+  if (constraints) {
+    const asserts = constraints.query.columns .filter (c => c.as[0] !== '_' && !((c.as || c.ref[0]) in pk))
+    return SELECT.from (constraints, pk) .columns (asserts)
+  } else {
+    const asserts = _collect_asserts4 (req.target)
+    return SELECT.from (req.target, pk) .columns (asserts)
+  }
+}
 
-  // Support subject refs to base entities as arguments
-  if (x?.ref) [ x, pk ] = [ x.ref +'.constraints', pk.ID||pk ]
+function _collect_asserts4 (entity) {
+  const cols = []
+  for (let e of entity.elements) {
+    if (e.$struct) continue // skip structured elements
+    let xpr = _asserts4 (e)
+    if (xpr) cols.push({ xpr, as: e.name })
+  }
+  return cols
+}
 
-  // Run the constraints check query
-  const constraints = typeof x === 'string' ? cds.model.definitions[x] || cds.error `No such constraints view: ${x}` : x
-  return SELECT.from (constraints, pk, columns.length && columns)
+function _asserts4 (e) {
+  let xpr = e?.['@assert']?.xpr; if (!xpr) return
+  let inherited = _asserts4 (e.parent.__proto__.elements?.[e.name])
+  if (inherited) xpr = [ ...inherited.slice(0,-1), ...xpr.slice(1) ]
+  return xpr
+}
 
-  // Collect and throw errors, if any
-  .then (rows => (rows.map ? rows : [rows]).map (checks => {
-    const failed = {}; for (let c in checks) {
-      if (c in constraints.keys) continue
-      if (c[0] == '_') continue
+function _handle_results (rows) {
+  if (!Array.isArray(rows)) rows = [rows]
+  return rows.map (checks => {
+    const failed = {}; for (let c in checks)
       if (checks[c]) failed[c] = checks[c]
-    }
     if (Object.keys(failed).length) throw cds.error `Invalid input: ${failed}`
     return checks
-  }))
+  })
 }
 
-
-// Helpers
-const _is_constraints = x => x.ref || x.is_entity || typeof x === 'string'
+function _key_from_data (req) {
+  const pk = {}
+  for (let k in req.target.keys)
+    if (k in req.data) pk[k] = req.data[k]
+  return pk
+}
\ No newline at end of file

From 069260426eea0a27bf81443fc42cfc73822b28eb Mon Sep 17 00:00:00 2001
From: Daniel Hutzel <daniel.hutzel@sap.com>
Date: Mon, 25 Aug 2025 14:03:28 +0200
Subject: [PATCH 5/7] .

---
 .../srv/etc/validation-asserts.cds            | 20 +++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/tests/dynamic-constraints/srv/etc/validation-asserts.cds b/tests/dynamic-constraints/srv/etc/validation-asserts.cds
index c03836e..d3bfb98 100644
--- a/tests/dynamic-constraints/srv/etc/validation-asserts.cds
+++ b/tests/dynamic-constraints/srv/etc/validation-asserts.cds
@@ -1,8 +1,21 @@
 using { sap.capire.bookshop.Books } from '@capire/bookshop';
 
+// @mandatory
+// @readonly
+// @hidden / visible / inapplicable
+// @assert.range
+// @assert.format
+// @assert.target
+
 // Following are invariant constraints declared on domain model entity
 annotate Books with {
 
+  // manual two-step mandatory constraint
+  // title @assert.constraint: {
+  //   not_null: { condition: (title is not null), message: 'is missing' },
+  //   not_empty: { condition: (trim(title) != ''), message: 'must not be empty' },
+  // };
+
   // manual two-step mandatory constraint
   title @assert: (case
     when title is null  then 'is missing'
@@ -11,7 +24,7 @@ annotate Books with {
 
   // range check
   stock @assert: (case
-    when stock < 0 then 'must not be negative'
+    when stock <= 0 then 'must not a positive number'
   end);
 
   // range check
@@ -35,13 +48,16 @@ annotate Books with {
 annotate AdminService.Books with {
 
   author @assert: (case
-    when sum(author.books.price) > 111 then author.name || ' already earned too much with his/her books'
+    when sum(author.books.price) > 111 then author.name || ' already earned too much with their books'
     when count(author.books.ID) -1 > 1 then author.name || ' already wrote too many books'
     // FIXME: ^^^^^^^^^^^^^^^^ cqn4sql doesn't support count(author.books) yet
   end);
 
+  price @mandatory: (exists author.books.genre[name = 'Drama']);
+
   price @assert: (case
     when price is null and exists author.books.genre[name = 'Drama']
     then 'Price must be specified for books by drama queens'
   end);
+
 }

From 68ddcd0557cbb2b37aa57e7cf1bba9d0d5bc355b Mon Sep 17 00:00:00 2001
From: Daniel Hutzel <daniel.hutzel@sap.com>
Date: Mon, 25 Aug 2025 14:46:01 +0200
Subject: [PATCH 6/7] .

---
 bookshop                                         |  2 +-
 bookstore                                        |  2 +-
 common                                           |  2 +-
 orders                                           |  2 +-
 reviews                                          |  2 +-
 shared-db                                        |  2 +-
 support                                          |  2 +-
 .../srv/etc/validation-asserts.cds               | 16 ++++++++++++----
 8 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/bookshop b/bookshop
index b97669d..721a529 160000
--- a/bookshop
+++ b/bookshop
@@ -1 +1 @@
-Subproject commit b97669df334a4013a1302636ea12a931415eb61b
+Subproject commit 721a52904521df772ace81fb468340575b54765a
diff --git a/bookstore b/bookstore
index 05a9e65..1fd04f2 160000
--- a/bookstore
+++ b/bookstore
@@ -1 +1 @@
-Subproject commit 05a9e65870c317d4cc7c87964052b306fd9b5e19
+Subproject commit 1fd04f29840c81a8cc3072589bc411af85c7c7f6
diff --git a/common b/common
index 56a29d5..f58e886 160000
--- a/common
+++ b/common
@@ -1 +1 @@
-Subproject commit 56a29d5370271f99b7aace6d562ab868193b792e
+Subproject commit f58e8861e359f773c69c0a4fb4292ec73ba26b15
diff --git a/orders b/orders
index 9cfe5d5..af390da 160000
--- a/orders
+++ b/orders
@@ -1 +1 @@
-Subproject commit 9cfe5d50b0b24840f2b5349d4c862ff03fd84c58
+Subproject commit af390da8b74b4460f01f73c27373e0e16c3c73b2
diff --git a/reviews b/reviews
index f2d1db2..207e086 160000
--- a/reviews
+++ b/reviews
@@ -1 +1 @@
-Subproject commit f2d1db225e54438d6055f5d8bfefeeb02aa73f3b
+Subproject commit 207e0869f3d94564d863d7cce3e780a3d16633ef
diff --git a/shared-db b/shared-db
index c5c923b..af1ab4a 160000
--- a/shared-db
+++ b/shared-db
@@ -1 +1 @@
-Subproject commit c5c923b23ce9d93455343c02fe236f7b2b904327
+Subproject commit af1ab4a68d71c8b63e7e2c5b462f32be85f8eb67
diff --git a/support b/support
index 23b495f..73ad0b8 160000
--- a/support
+++ b/support
@@ -1 +1 @@
-Subproject commit 23b495f94c41663c49b1da1e4598c3d1eedbc2f5
+Subproject commit 73ad0b814b0990677dda5569637f61425cfee2c5
diff --git a/tests/dynamic-constraints/srv/etc/validation-asserts.cds b/tests/dynamic-constraints/srv/etc/validation-asserts.cds
index d3bfb98..7b697fe 100644
--- a/tests/dynamic-constraints/srv/etc/validation-asserts.cds
+++ b/tests/dynamic-constraints/srv/etc/validation-asserts.cds
@@ -29,24 +29,32 @@ annotate Books with {
 
   // range check
   price @assert: (case
+    // when price is not null and not price between 0 and 500 then 'must be between 0 and 500'
     when price <= 0 or price > 500 then 'must be between 0 and 500'
-   end);
+  end);
 
   // assert target check
+  // genre @assert: (case
+  //   when genre is not null and not exists genre then 'does not exist'
+  // end);
+
   genre @assert: (case
-    when genre is not null and not exists genre then 'does not exist'
-   end);
+    when genre is null then null // genre may be null
+    when not exists genre then 'does not exist'
+  end);
 
-  // multiple constraints: mandatory + assert target + special
+  // multiple constraints: mandatory + assert target, ...
   author @assert: (case
     when author is null then 'is missing'
     when not exists author then 'does not exist'
   end);
 }
 
+
 // Following need to go on service-level entity, as rewriting would fail for CatalogService
 annotate AdminService.Books with {
 
+  // ... + special
   author @assert: (case
     when sum(author.books.price) > 111 then author.name || ' already earned too much with their books'
     when count(author.books.ID) -1 > 1 then author.name || ' already wrote too many books'

From 9253f9289ca9516b8214d92524849243ee170621 Mon Sep 17 00:00:00 2001
From: Daniel Hutzel <daniel.hutzel@sap.com>
Date: Mon, 25 Aug 2025 14:53:19 +0200
Subject: [PATCH 7/7] .

---
 tests/dynamic-constraints/srv/etc/validation-asserts.cds | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/dynamic-constraints/srv/etc/validation-asserts.cds b/tests/dynamic-constraints/srv/etc/validation-asserts.cds
index 7b697fe..c4eb087 100644
--- a/tests/dynamic-constraints/srv/etc/validation-asserts.cds
+++ b/tests/dynamic-constraints/srv/etc/validation-asserts.cds
@@ -2,7 +2,8 @@ using { sap.capire.bookshop.Books } from '@capire/bookshop';
 
 // @mandatory
 // @readonly
-// @hidden / visible / inapplicable
+// @hidden @visible @inapplicable
+
 // @assert.range
 // @assert.format
 // @assert.target