Query Mode
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The query mode of the Clients allows you to bind external variables to a query
and evaluate the query in an iterative manner. The query()
function of the
Session
instance returns a new query instance.
Usage
The query execution works as follows:
- Create a new session instance with hostname, port, username and password.
- Call
query()
with your XQuery expression to get a query object. - Optionally bind variables to the query with one of the
bind()
functions. - Optionally bind a value to the context item via
context()
. - Iterate through the query object with the
more()
andnext()
functions. - As an alternative, call
execute()
to get the whole result at a time. info()
gives you information on query evaluation.options()
returns the query serialization parameters.- Don't forget to close the query with
close()
.
PHP Example
Taken from our repository:
<?php /* * This example shows how queries can be executed in an iterative manner. * Documentation: http://basex.org/api * * (C) BaseX Team 2005-15, BSD License */ include("BaseXClient.php"); try { // create session $session = new Session("localhost", 1984, "admin", "admin"); try { // create query instance $input = 'declare variable $name external; '. 'for $i in 1 to 10 return element { $name } { $i }'; $query = $session->query($input); // bind variable $query->bind("$name", "number"); // print result print $query->execute()."\n"; // close query instance $query->close(); } catch (Exception $e) { // print exception print $e->getMessage(); } // close session $session->close(); } catch (Exception $e) { // print exception print $e->getMessage(); } ?>
Changelog
- Version 7.2
- Added:
context()
function