As I do the same in my code:

* you can use xquery:eval as mentioned but: ** be careful how to pass in the db:open() or collection(). It is quite easy to prevent BaseX from seeing that there are indexes and use them ** xquery:eval uses global locking. So no writing while such a query is running. As I understand it as many queries as you like can read at the same time.

* you can use jobs:eval with cache: true() and background the actual job and have the option to lock only what you need but: ** you can dead lock between the background and the RestXQ request if you are not careful ** there is a chance to accept to many RestXQ requests and so the actual query is never processed (counter measer: Option FAIRLOCK) ** you have to check for unwanted statements using jobs:parse so you catch updates if you don't want write access or starting more jobs in that XPath/XQuery they pass

Both cases allow access to the full library of functions available in exist (apart from updating ones in xquery:eval). One thing to be aware about is the potential of abuse of httpclient:*.

Because I cannot use global locking and do have updates mixed with read requests I have invested some time to get the jobs:eval right. But I'm also not the seasoned BaseX developer yet.

Best regards

Omar

Am 02.02.2018 um 16:06 schrieb France Baril:

I'm trying to do something similar to this because I'll have to deal with xpaths provided by end users as parameters to a rest query:

var xpath='div/p'

for $i in db:open('en-us'){$xpath} return $i

I saw that it's possible to do it with other tools, but I didn't find if it's possible with xquery and BaseX.

How SQL dbs do it:

SET @XML1='
<Root>
    <Device>
        <Inspection>
<Status>OK</Status>
        </Inspection>
    </Device>
</Root>'

SET @PATH = '/Root[1]/Device[1]/Inspection[1]/Status[1]'

SELECT @XML1.query(@PATH)

Any suggestion that doesn't involve analyzing the query string and trying to rebuild it in some way?

-- France Baril Architecte documentaire / Documentation architect france.baril@architextus.com mailto:france.baril@architextus.com