Terry P wrote:
> Are there any tools (java classes, tag libraries) which can translate
> xpath statements into a SQL query?
> 
> Given an xpath query which has a predicate that filters node values or
> attributes, I want help constructing the Where clause of a SQL
> statement that will mirror the expressions and functions contained in
> the predicate.
> 
> Such a tool may require an XML to DB mapping or it would need to make
> assumptions about the structure of the document and the tables.
> 
> Thanks for any advice.
> 
> Terry

What sory of database are you talking about?
A ordinary relational database? Or an XML-database.
Xml-databases are new and not very fast, but there is extensive research in xml-database-system.
Those system support xpath and xquery as query languages.

I'f you want to map xpath onto sql, then your're right: you need some
rules about how xml is mapped onto the relational database.
With those rules you could map xpath expression to sql expressions.

I don't know wether they exists. I myself have my own mapping rules,
rather simplistic rules but it does the job for me.