Select multiple values and compare them using XQuery or XPath?

Question

I have the following XML:

<items>
 <item min="1" max="3"> </item>
 <item min="2" max="7"> </item>
 <item min="1" max="2"> </item>
</items>

And I need to check for every item if min is always smaller than max. Expected output for this input would be false as @min="2" is not smaller than @max="2" .

I've tried something similar to:

every $min,$max  in //item/@min, //item/@max satisfies ...

But that's obviously not working. Any ideas?

Answer 1

You don't need to use satisfies , just invert the condition and use not(...) .

This query will return all @min attributes that fulfill the condition:

//item/@min[not(. >= //item/@max)]

If you want to use satisfies , use this query:

//item/@min[every $max in //item/@max satisfies . < $max]

---

If you want to know whether all elements fulfill the condition, check no elements do not fulfill it:

not(//item/@min[. >= //item/@max])

You could even do without a predicate (XPath/XQuery comparisons have a set-like semantic, this means true iff one @min value that is equal or greater than one @max value):

not(//item/@min >= //item/@max)

Answer 2

您没有非常清楚地表达您的要求，但听起来好像您希望最高@min小于最低@max，这将是

max(item/@min) lt min(item/@max)