Querying a DBXML from Within

Question

Hi,
I am relatively new to the concept of DBXML, but am loving every bit of it, especially our project is SOA based.
My Question is that we can do this in shell
dbxml>q 'collection()//x/string()'
now what I want to ask is that, is there a way to store the Queries in kind of an XML file contained in a container using putdocument() such that we could do something like
The Query.xml file
<Q><q>collection()//x/string()</q></Q>
the query in shell as
dbxml> q 'let $i:=collection//q/string()
return execute($i)'
or something like that.
Meaning the queries are stored in the DBXML container itself and are looked up as required and then executed, something like a view or Stored procedure functionality, so that we can keep these query files in container itself for better maintainability and manageability.
Thanks

Answer 1

Hi,
Storing the queries as metadata inside a container may provide the functionality that you want. Metadata is information related in some way to a document but maintained separately.
The string that represents the query can be stored as metadata for a dedicated document (this document can be an empty one, as it doesn't need to contain any information) that represent the query. You can retrieve the query string than use it to subsequently perform the get operations you want. The dbxml shell is somehow limited in that it doesn't allow you to redirect and execute the query represented by the string result of a previous query (contextQuery is used to query against the last results as the context item). So, you can implement this programmatically using one of the APIs available.
Or you may want to store all your queries in a separate dedicated container.
A short example in the dbxml shell would be:
- store a query as metadata for an empty document inside the container:
dbxml> setMetadata q1 "" querystring string "collection()//x/string()"
- retrieve the query from the q1 document's metadata:
dbxml> query "doc('container.dbxml/q1')/dbxml:metadata('querystring')"
- programmatically you would use the stored query and execute it against the container; this could will imply XmlManager::query, XmlResults::next, XmlValue::asString and another XmlManager::query call, or alternatively using XmlQueryExpression::execute.
Regards,
Andrei