A posting from Howard Katz (Fatdog Software) announces the Version 0.99 release of 'XML Query Engine' with with early (0.25) W3C XQuery support. "If you want some introductory hands-on exploration of basic XQuery syntax, a free evaluation version of the engine is available. You can now select either XQL or XQuery for your query language front end. This release provides a first cut at a very limited implementation of the full XQuery grammar. This implementation supports FLWR expressions, element constructors, a limited range of XPath expressions on elements only, simple predicates testing element existence and text equality, and that's about it. The good news is that with the exception of expression lists, FLWRs can be explored in almost full recursive generality, and the features that are in place can be employed against actual data. Here's a sample query: <results> FOR $book IN //book FOR $author IN $book/author WHERE $author/first = 'Dan' RETURN <DanTheMan> $author </DanTheMan> </results> . XML Query Engine (XQEngine for short) is a full-text search engine component for XML. It lets you search small to medium-size collections of XML documents for boolean combinations of keywords, much as web-based search engines let you do for HTML. Queries are specified using XQL, a de facto standard for querying XML documents that is nearly identical to the simplified form of XPath. Queries expressed in XQL are much more expressive and powerful than the standard search interfaces available through web-based search engines." Note also the online document by Katz "Introduction to XQuery."
"XML Query Engine is a search engine tool for XML. It's a JavaBean component that lets you index and then search your XML documents for element, attribute, and full-text content. It can index up to 32,768 documents using a SAX parser of your choice. The index, once built, can be queried using XQL, a de facto standard for searching XML that is, very nearly, a proper subset of XPath. XML Query Engine extends XQL's syntax to provide a full-text capability, something lacking in standard XQL. This lets you say such things as 'Find me the first paragraph within either a division or a chapter that contains both the words 'xml' and 'xsl' or 'Give me a list of all elements containing an href attribute which points to a '.com' organization.' XML Query Engine is an embeddable component that's callable from your application. It requires some straightforward Java programming to wire the query engine to your front-end code. The engine uses a result-listener architecture to deliver its results: You register an XQL result listener with the engine before calling your first query."
Principal references:
- XML Query Engine web site
- W3C XQuery: A Query Language for XML
- Download
- Introduction to XQuery
- XQL FAQ web site
- Contact: Howard Katz
- "XML and Query Languages" - Main reference page.