Skip to content

Java: Handling Compositions and Aliased Paths in Projections #2017

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
+4 −0
Open

Java: Handling Compositions and Aliased Paths in Projections #2017

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 4 additions & 0 deletions java/working-with-cql/query-execution.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -282,6 +282,10 @@ UPDATE entity OrderView2
- [Deep write](./query-execution#deep-insert-upsert) via (aliased) compositions (*lineItems*) is supported if there are corresponding compositions (*items*) in the underlying entity definition. Deep write via compositions that are only defined in the view (for example via [mixins](../../cds/cql#association-definitions)) is not supported and the data is ignored.
- [Path expressions](../../cds/cql#path-expressions) over compositions *of one* (*header.status*) are writable. For [inserts](./query-api#insert), the view must expose all *not null* elements of the target entity and the data must include values for all of them. In the example above, the order header must have a generated key to support inserting new orders with a value for *headerStatus*.

::: warning Handling Compositions and Aliased Paths in Projections
For projections that include *to-one* compositions (*header*) and aliased paths over these compositions (*headerStatus*), write structured data via the composition and make the aliased path [@readonly](../../guides/providing-services#readonly). Don't use data for the aliased path together with structured data for the composition in the same statement.
:::

::: warning Path Expressions over Associations
Path expressions navigating *associations* (*header.customer.name*) are [not writable](#cascading-over-associations) by default. To avoid issues on write, annotate them with [@readonly](../../guides/providing-services#readonly).
:::
Expand Down