Metacat

<!--

  * pathquery.dtd

  *

  *      Authors: Matt Jones

  * Organization: National Center for Ecological Analysis and Synthesis

  *    Copyright: 2000 Regents of the University of California and the

  *               National Center for Ecological Analysis and Synthesis

  *  For Details: http://www.nceas.ucsb.edu/

  *      Created: 13 June 2000

  *    File Info: '$Id: pathquery.dtd 403 2000-08-23 17:33:45Z berkley $'

  *

  * This DTD describes the structure and content of XML documents used

  * to represent, store, and exchange a simple path-based query expression.

  * This syntax represents a small subset of the capabilities of the XPath 

  * language (http://www.w3.org/TR/xpath), and is intended as a simple

  * query language for the metadata catalog database (mcdb).  It is 

  * intended that all expressions in this language can be mapped directly

  * into XPath syntax, but not all Xpath expressions can be mapped into this

  * syntax.

  *

  * Although ideally we would implement the query language as either the full

  * XPath language or as one of the emerging XML query languages (like

  * XML-QL or XQL), in practice this would be an involved undertaking that

  * doesn't necessarily have high payoffs.  But we will revisit this issue and

  * determine later whether these full-featured technologies are warranted

  * after we have some experience with a simpler implementation such as this.

-->

<!-- Overall query container -->

<!ELEMENT pathquery (meta_file_id, querytitle, returndoctype*, returnfield*, 

                     querygroup)>

<!-- The version of this query specification -->

<!ATTLIST pathquery version CDATA #FIXED "1.0">

<!-- a unique identifier for this query document -->

<!ELEMENT meta_file_id (#PCDATA)>

<!-- a descriptive title for this query document -->

<!ELEMENT querytitle (#PCDATA)>

<!-- optional doctype filter - only documents with this type are returned -->

<!ELEMENT returndoctype (#PCDATA)>

<!ELEMENT returnfield (#PCDATA)>

<!-- A group of related query terms -->

<!ELEMENT querygroup ( (queryterm|querygroup)+ )>

<!-- the boolean expression used to combine the query terms in this group -->

<!ATTLIST querygroup operator (INTERSECT|UNION) #REQUIRED>

<!-- a query term is the atomic unit of a query that can be translated

     to a single SELECT statement -->

<!ELEMENT queryterm (value, pathexpr?)>

<!-- a boolean flag indicating whether matches should be case-sensitive or

     case-independent for this queryterm, one of: true|false

     and searchmode is the type of match to perform against the text value -->

<!ATTLIST queryterm casesensitive (true|false) #REQUIRED

                    searchmode 

        (contains|starts-with|ends-with|matches-exactly) #REQUIRED>

<!-- the text value for which we are searching -->

<!ELEMENT value (#PCDATA)>

<!-- the path to the TEXT node used to constrain the query -->

<!ELEMENT pathexpr (#PCDATA)>

<!-- End of file -->