# Archetype based query

**Category:** [Technical (archive)](https://discourse.openehr.org/c/technical-archive/156)
**Created:** 2004-11-03 22:33 UTC
**Views:** 1
**Replies:** 0
**URL:** https://discourse.openehr.org/t/archetype-based-query/12027

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## Post #1 by @Sam

Dear Tom and Andrew

It is clear that we need a standard notation for expressing queries into the openEHR space\. I am sure you have this underway but the statements must address queries into both levels of the model \- the reference model and the archetype stamps in the reference model\.

1\. The statements that relate to the Reference Model include:

  \- Time \(Composition time, Observation\.History\.Event\.time\)  \-
\- Return type Folder/Composition/Section/Entry/\{data|protocol|state\}/Cluster/Element/Value
  \- Committer, participation

2\. Statements that relate to archetype

  \- May have an archetype at any valid level in the reference model \- archetype specifies the rm class in the name
  \- Path statement to the level of the return type \- this could determine the return type
  \- Where statements or conditions

These could probably all be expressed in XQuery \- which is \(I think\) what we should be concentrating on to get the data out\.

We need to formulate this as soon as possible\. I wonder if there are many people out there who have begun to working with XQuery?

Cheers, Sam

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**Canonical:** https://discourse.openehr.org/t/archetype-based-query/12027
**Original content:** https://discourse.openehr.org/t/archetype-based-query/12027