[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

RE: Early Draft Review: XQuery for Java (JSR 225)

• To: "'Burak Emir'" <Burak.Emir@e...>
• Subject: RE: Early Draft Review: XQuery for Java (JSR 225)
• From: "Michael Kay" <michael.h.kay@n...>
• Date: Fri, 28 May 2004 10:16:29 +0100
• Cc: "'Jonathan Robie'" <jonathan.robie@d...>,<xml-dev@l...>,<jsr-225-comments@j...>
• In-reply-to: <40B6F9F1.1080104@e...>
• Thread-index: AcREjtv8rkg+bOMuSbOPEfRHfP3S1QABGBqQ

 
> In Pizza (or Haskell or ocaml or Scala) one would do like this:
> 
> Var b = Var();
> Var authors = Var();
> FLOWR(
>    For( b, Doc("books.xml").descOrSelf("bib:book"), 
>          /* for $b in doc("books.xml") // bib:book */
>    Let( authors, b.descOrSelf("bib:author") ),
>          /* let $authors = b // bib:author */
>    _,
>    _,
>    Return(
>        element("result"),
>        Sequence( b.child("bib:title"), authors )
>     )  /* return <result>{ $b/bib:title, $authors }</result> */
> )
> 

But that's not exactly XQuery, is it? It's a new query language of your own
invention. This approach requires a new query language to be designed for
each host language. You haven't started to address the problems, which range
from incompatible syntax for identifiers between the programming language
and the database, to incompatible semantics for operators like "=".

I think this example absolutely demonstrates the difficulties that arise
with database sublanguages, and the reason they became unpopular.

Michael Kay

• Follow-Ups:
  • Re: Early Draft Review: XQuery for Java (JSR 225)
    • From: Burak Emir <Burak.Emir@e...>

• References:
  • Re: Early Draft Review: XQuery for Java (JSR 225)
    • From: Burak Emir <Burak.Emir@e...>

• Prev by Date: Re: Early Draft Review: XQuery for Java (JSR 225)
• Next by Date: RE: Early Draft Review: XQuery for Java (JSR 225)
• Previous by thread: Re: Early Draft Review: XQuery for Java (JSR 225)
• Next by thread: Re: Early Draft Review: XQuery for Java (JSR 225)
• Index(es):
  • Date
  • Thread