@assert.unique not working with deep structures

[tatiana_fetecua]

Hi everyone,

I have a cds schema that has the composition entities defined inside the parent entity, for example:

entity Product : cuid {
  type       : StyleType;
  style      : Style;
  categories : Composition of many {
                 key ID           : UUID;
                     categoryType : String(1);
                     categoryNumber: String(1);
               }
}

And I want to define an @assert.unique for ID up__ID and Category type :

@assert.unique.style : [
  ID,
  up__ID,
  categoryType,
  categoryNumber,
]

But I get compile messages errors like this:

message: '“@assert.unique.style”: “categoryType” has not been found'.

If I define my categories entity outside and I define the @assert.unique.style like this:

entity Product : cuid {
  type       : StyleType;
  style      : Style;
  categories : Composition of many Categories on categories.parent = $self
}
@assert.unique.style : [
  parent,
  categoryType,
  categoryNumber,
]
entity Categories: cuid {
  parent: Association to Product;
  categoryType : String(1);
  categoryNumber : String(1);
}

it works, but I want to know if it is possible to define it when the composition of many is not defined outside, because this will save me a lot of work to redefine my schema, views, etc.

Thanks,

Tatiana F.

[patricebender · Accepted solution]

You can do that by using the `annotate` directive:

annotate Product.categories with @assert.unique.style : [
  ID,
  up_, // you have to set the unique constraint on the association
  categoryType,
];

However, I think the unique constraint in this combination is pretty useless, as "ID" and "up_" are the primary key tuple, hence there can never be more then one record stored with the same "ID" and "up_" combination. Consequently there can never be two rows where "ID", "up_" and "categoryType" are the same.

[tatiana_fetecua · Accepted solution]

Hi Patrice,

First, thanks for the response, I have implemented the annotation directive and it is working now, and yes my example was not complete, it was more to illustrate the entity definition.

Tatiana F.

[patricebender · Accepted solution]

glad I could help! 🙂