validate an element for unique value in multiple occuranes

[Priti Shah]

Hi,

I have this xml which allows multiple occurences of log file locations.

<some-element>
<log>log location 1</log>
<log>log location 2</log>
<log>log location 3</log>
<log>log location 4</log>
</some-element>

Now in my schema I want to check for max occurances 4 which I can do using 'maxOccur' attribute. But I also want to make sure that all 4 elements should have different values.
How can I do that ?

Thanks in advance.

[Madhav Lakkapragada]

Welcome to Javaranch.
[Sorry about the delayed reply, I had to dust-off my XSD book to answer this.]

The construct you are looking for is xsd:unique.

Use something like -

<xsd:unique name="SomeUniqueValue">
    <xsd:selector xpath="*/log"/>
    <xsd:field xpath="."/>
</xsd:unique>

You need to place this in the context in which you want to impose the uniqueness constraint. More homework to do.......

- m