MarkLogic 12 EA 2 Product Documentation

cts:element-query

cts:element-query(
   $element-name as xs:QName*,
   $query as cts:query
) as cts:element-query

Summary

Constructs a query that matches elements by name with the content constrained by the query given in the second parameter. Searches for matches in the specified element and all of its descendants. If the query specified in the second parameter includes any element attribute sub-queries, it will search attributes on the specified element and attributes on any descendant elements. See the second example below).

Usage Notes

Enabling both the word position and element position indexes ("word position" and "element word position" in the database configuration screen of the Admin Interface) will speed up query performance for many queries that use cts:element-query. The position indexes enable MarkLogic Server to eliminate many false-positive results, which can reduce disk I/O and processing, thereby speeding the performance of many queries. The amount of benefit will vary depending on your data.

You can query for the existence of an element by specifying an empty cts:and-query as the second parameter. For example, the following will match any instance of the specified element:

  cts:element-query(xs:QName("my-element"),
    cts:and-query( () ))
  

Example

  cts:search(//module,
    cts:element-query(
      xs:QName("function"),
      "MarkLogic Corporation"))

  => .. relevance-ordered sequence of 'module' elements
  ancestors (or self) of elements with QName 'function'
  and text content containing the phrase 'MarkLogic
  Corporation'.

Example

let $x := <a attr="something">hello</a>
return
cts:contains($x, cts:element-query(xs:QName("a"),
   cts:and-query((
     cts:element-attribute-word-query(xs:QName("a"),
         xs:QName("attr"), "something"),
     cts:word-query("hello")))))
(: returns true :)