Moved all @Assert, @readonly, @mandatory to guides/services/constraints

Author: danjoa

cds/annotations.md

@@ -36,11 +36,11 @@ uacp: Used as link target from Help Portal at https://help.sap.com/products/BTP/
 
 | Annotation          | Description                                                          |
 |---------------------|----------------------------------------------------------------------|
-| `@readonly `        | see [Input Validation](../guides/providing-services#readonly)       |
-| `@mandatory`        | see [Input Validation](../guides/providing-services#mandatory)      |
-| `@assert.target`    | see [Input Validation](../guides/providing-services#assert-target)  |
-| `@assert.format`    | see [Input Validation](../guides/providing-services#assert-format)  |
-| `@assert.range`     | see [Input Validation](../guides/providing-services#assert-range)   |
+| `@readonly `        | see [Input Validation](../guides/services/constraints#readonly)       |
+| `@mandatory`        | see [Input Validation](../guides/services/constraints#mandatory)      |
+| `@assert.target`    | see [Input Validation](../guides/services/constraints#assert-target)  |
+| `@assert.format`    | see [Input Validation](../guides/services/constraints#assert-format)  |
+| `@assert.range`     | see [Input Validation](../guides/services/constraints#assert-range)   |
 
 
 
@@ -91,8 +91,8 @@ Intrinsically supported OData Annotations:
 
 | Annotation             | Description                                                      |
 |------------------------|------------------------------------------------------------------|
-| `@Core.Computed`       | see [Providing Services](../guides/providing-services#readonly) |
-| `@Core.Immutable`      | see [Providing Services](../guides/providing-services#readonly) |
+| `@Core.Computed`       | see [Providing Services](../guides/services/constraints#readonly) |
+| `@Core.Immutable`      | see [Providing Services](../guides/services/constraints#readonly) |
 | `@Core.MediaType`      | see [Media Data](../guides/providing-services#serving-media-data)                          |
 | `@Core.IsMediaType`    | see [Media Data](../guides/providing-services#serving-media-data)                          |
 | `@Core.IsUrl`          | see [Media Data](../guides/providing-services#serving-media-data)                          |

cds/cdl.md

@@ -482,7 +482,7 @@ entity Bar {
 
 An element definition can be prefixed with modifier keyword `virtual`. This keyword indicates that this element isn't added to persistent artifacts, that is, tables or views in SQL databases. Virtual elements are part of OData metadata.
 
-By default, virtual elements are annotated with `@Core.Computed: true`, not writable for the client and will be [silently ignored](../guides/providing-services#readonly). This means also, that they are not accessible in custom event handlers. If you want to make virtual elements writable for the client, you explicitly need to annotate these elements with `@Core.Computed: false`. Still those elements are not persisted and therefore, for example, not sortable or filterable. Further, during read requests, you need to provide values for all virtual elements. You can do this by using post-processing in an `after` handler.
+By default, virtual elements are annotated with `@Core.Computed: true`, not writable for the client and will be [silently ignored](../guides/services/constraints#readonly). This means also, that they are not accessible in custom event handlers. If you want to make virtual elements writable for the client, you explicitly need to annotate these elements with `@Core.Computed: false`. Still those elements are not persisted and therefore, for example, not sortable or filterable. Further, during read requests, you need to provide values for all virtual elements. You can do this by using post-processing in an `after` handler.
 
 ```cds
 entity Employees {
@@ -695,7 +695,7 @@ entity Order {
 }
 ```
 
-To enforce your _enum_ values during runtime, use the [`@assert.range` annotation](../guides/providing-services#assert-range).
+To enforce your _enum_ values during runtime, use the [`@assert.range` annotation](../guides/services/constraints#assert-range).
 For localization of enum values, model them as [code list](./common#adding-own-code-lists).
 
 <br>

guides/databases.md

@@ -916,7 +916,7 @@ CREATE TABLE Books_texts (
 ::: warning Database constraints aren't intended for checking user input
 Instead, they protect the integrity of your data in the database layer against programming errors. If a constraint violation occurs, the error messages coming from the database aren't standardized by the runtimes but presented as-is.
 
-→ Use [`@assert.target`](providing-services#assert-target) for corresponding input validations.
+→ Use [`@assert.target`](services/constraints#assert-target) for corresponding input validations.
 :::
 
 ## Standard Database Functions