Difference between revisions of "Query Mode"
Jump to navigation
Jump to search
m (Text replacement - "syntaxhighlight" to "pre") Tags: Mobile web edit Mobile edit |
|||
(21 intermediate revisions by 3 users not shown) | |||
Line 1: | Line 1: | ||
− | <p>The query mode of the [[ | + | <p>The query mode of the [[Clients]] allows you to bind external variables to a query |
− | and evaluate the query in an iterative manner. | + | and evaluate the query in an iterative manner. The <code>query()</code> function of the |
− | of the <code>Session</code> instance | + | <code>Session</code> instance returns a new query instance.</p> |
− | |||
− | |||
==Usage== | ==Usage== | ||
− | + | The query execution works as follows: | |
# Create a new session instance with hostname, port, username and password. | # Create a new session instance with hostname, port, username and password. | ||
− | # Call | + | # Call <code>query()</code> with your XQuery expression to get a query object. |
− | # Optionally bind variables to the query with the <code>bind()</code> | + | # Optionally bind variables to the query with one of the <code>bind()</code> functions. |
− | # | + | # Optionally bind a value to the context item via <code>context()</code>. |
− | # Iterate through the query object with the <code>more()</code> and <code>next()</code> functions | + | # Iterate through the query object with the <code>more()</code> and <code>next()</code> functions. |
− | # As an alternative, call <code>execute()</code> to get the whole result at a time | + | # As an alternative, call <code>execute()</code> to get the whole result at a time. |
− | # | + | # <code>info()</code> gives you information on query evaluation. |
− | # | + | # <code>options()</code> returns the query serialization parameters. |
+ | # Don't forget to close the query with <code>close()</code>. | ||
− | ==Example | + | ==PHP Example== |
− | <pre | + | Taken from our [https://github.com/BaseXdb/basex/blob/master/basex-api/src/main/php/QueryBindExample.php repository]: |
+ | |||
+ | <pre lang="php"> | ||
<?php | <?php | ||
/* | /* | ||
Line 26: | Line 27: | ||
* Documentation: http://basex.org/api | * Documentation: http://basex.org/api | ||
* | * | ||
− | * (C) BaseX Team 2005- | + | * (C) BaseX Team 2005-15, BSD License |
*/ | */ | ||
include("BaseXClient.php"); | include("BaseXClient.php"); | ||
Line 32: | Line 33: | ||
try { | try { | ||
// create session | // create session | ||
− | $session = new Session("localhost", 1984, "admin", " | + | $session = new Session("localhost", 1984, "admin", "..."); |
try { | try { | ||
Line 43: | Line 44: | ||
$query->bind("$name", "number"); | $query->bind("$name", "number"); | ||
− | // | + | // print result |
− | + | print $query->execute()."\n"; | |
− | |||
− | |||
− | |||
− | |||
− | |||
// close query instance | // close query instance | ||
− | + | $query->close(); | |
} catch (Exception $e) { | } catch (Exception $e) { | ||
Line 69: | Line 65: | ||
</pre> | </pre> | ||
− | + | =Changelog= | |
− | + | ||
− | + | ;Version 7.2 | |
− | + | ||
+ | * Added: {{Code|context()}} function |
Latest revision as of 18:38, 1 December 2023
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[edit]
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[edit]
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", "...");
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[edit]
- Version 7.2
- Added:
context()
function