chore: add limiation section for deep write #1611
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guides/providing-services.md
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| 1. The on-condition of the composition only uses `=` operator | ||
| 2. Expressions are combined with the logical operator `AND` |
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and no negation not(...)
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also for deep writes?
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We don't support writing via on-conditions using negation.
not(...) can be rewritten using !=, which is covered by condition 1.
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somehow I misread the initial comment and though you do support not(...).
In essence, you also only support AND. OR/NOT are not supported generically?!.
We could emphasize this with
| 1. The on-condition of the composition only uses `=` operator | |
| 2. Expressions are combined with the logical operator `AND` | |
| 2. The predicates are only connected with the logical operator `AND` |
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That's correct, writing via on-conditions using OR or NOT is not supported.
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I've changed the sentence now to above proposal. fine for you?
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| Bad: | ||
| ```cds | ||
| entity Orders { | ||
| key ID : UUID; | ||
| title : String; | ||
| Items : Composition of many OrderItems on substring(title, 0, 1) <= 'F' or Items.pos > 12; | ||
| } | ||
| entity OrderItems { | ||
| key order : Association to Orders; | ||
| key pos : Integer; | ||
| descr: String; | ||
| } | ||
| ``` |
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I would avoid bad examples in the documentation There's always a risk that someone copies them.
Co-authored-by: Adrian Görler <[email protected]>
@agoerler @beckermarc Please double check whether these limitations also apply to CAP Java.
@renejeglinsky Do we have a better pattern to signal good/bad?