2013/4/25 Thomas Beale <thomas.beale at oceaninformatics.com>:
> On 25/04/2013 18:52, Diego Bosc? wrote:
>>
>> You can generate operations to deal with domain types, but then AQL
>> would be openEHR specific (you can call it OQL then). What I say is
>
>
> Diego,
>
> there is nothing openEHR-specific today in AQL, and allowing more complex
> primitive types like dates or codes or URIs doesn't change that. It will
> work just as well with any reference model from any industry. So I don't get
> your point here.
>
>
I'm not saying there is something openEHR specific right now in AQL,
I'm just saying that including additional requirements to deal with
domain types would make more difficult the implementation of a AQL
engine, and the queries generated this way ("domain type"-based
queries if you want) only would work in a environment ready to use
domain types.
My whole point is, domain types will give you more headaches in the
long run (problems with specialization, AQL, mapping, etc.) than
benefits.
>> that generating a path to specify a filter (and accessing it) is
>> direct when the domain type has been expanded, and not so easy if you
>> take it as it is. If you get the expanded path each time then the user
>> won't be able to tell where the AQL path comes from (it'll have
>> attributes he doesn't know about). I only see disadvantages working
>> with domain types in AQL.
>>
>
> but in that case you should be arguing that we should remove the Date/Time
> types and URIs etc. It's true, we can just limit ourselves to Integer / Real
> / String / Character / Boolean / Binary, but... why? It's just making life
> needlessly difficult as far as I can see.
>
Implied semantics will give you problem always (again, talking about
paths). The advantage of date/time & uris over codes is that the
former are strings which can be treated with convenient functions.
Codes would depend on the underlying archetype reference model to be
interpreted correctly.
>
> - thomas
>
>
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