Hello,
In order to better understand the semantics of AQL I try to rephrase the
problem I have:
Imagine an archetype "openEHR-EHR-CLUSTER.example.v1" that allows the
multiple existence of a specific contained field:
definition
CLUSTER[at0000] matches {
items cardinality matches {0..*; unordered} matches {
ELEMENT[at0001] occurrences matches {0..*} matches { value
matches { DV_TEXT matches {*} } }
}
}
Is it allowed to constrain this archetype in the WHERE part by accessing
the field within a path? :
SELECT e FROM EHR e CONSTAINS CLUSTER a[openEHR-EHR-CLUSTER.example.v1]
WHERE a/items[at0001]/value = 'test'
The problem I have with this query is that the path "a/items[at0001]" is
a list, so it perhaps cannot be extended with "value", because a list
does not have a field "value" but only the members of this list have
this field.
An alternative to the query above would be to resolve the list in the
FROM part by writing something like this:
SELECT e FROM EHR e CONSTAINS CLUSTER a[openEHR-EHR-CLUSTER.example.v1]
CONTAINS DV_TEXT b
WHERE b/value = 'test'
This would work in the above example, but would create further problems
if there are further elements in parallel to ELEMENT[at0001] that as
well contain DV_TEXTs and which would be matched as well by the
alternative query.
Greetings
Georg
--
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Dipl.-Inf. Georg Fette Raum: B001
Universität Würzburg Tel.: +49-(0)931-31-85516
Am Hubland Fax.: +49-(0)931-31-86732
97074 Würzburg mail: georg.fe...@uni-wuerzburg.de
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