#include <DbXml.hpp> class DbXml::XmlQueryExpression { public: XmlQueryExpression () virtual ~XmlQueryExpression () XmlQueryExpression (const XmlQueryExpression &) XmlQueryExpression & operator= (const XmlQueryExpression &) ... };
An XmlQueryExpression
represents a parsed
XQuery expression, and is created by a call to XmlManager::prepare.
Parsed XQuery expressions are useful because they allow the cost of
query parsing and optimization to be amortized over many evaluations.
If indices of a container that may be referenced by a parsed XQuery
expression are modified (e.g. add/drop an index) the
XmlQueryExpression
object should be
regenerated by the application.
The copy constructor and assignment operator are provided for this class. The class is implemented using a handle-body idiom. When a handle is copied both handles maintain a reference to the same body. This object is free threaded, and can be safely shared among threads in an application.