Technical FAQ
PHP Manual
CSS2 Manual
HTML Manual
JS Guide
JS Reference
PhpDock Manual
Nu-Coder Manual
PhpExpress Manual
PHP Joomla
Learn PHP
Last updated: Tue, 19 Sep 2006


(PHP 5)

sqlite_udf_decode_binary -- Decode binary data passed as parameters to an UDF


string sqlite_udf_decode_binary ( string data )

sqlite_udf_decode_binary() decodes the binary encoding that was applied to the parameter by either sqlite_udf_encode_binary() or sqlite_escape_string().

You must call this function on parameters passed to your UDF if you need them to handle binary data, as the binary encoding employed by PHP will obscure the content and of the parameter in its natural, non-coded form.

PHP does not perform this encode/decode operation automatically as it would severely impact performance if it did.


Example 1. binary-safe max_length aggregation function example

$data = array(
$db = sqlite_open(':memory:');
sqlite_query($db, "CREATE TABLE strings(a)");
foreach ($data as $str) {
    $str = sqlite_escape_string($str);
    sqlite_query($db, "INSERT INTO strings VALUES ('$str')");

function max_len_step(&$context, $string) 
    $string = sqlite_udf_decode_binary($string);
    if (strlen($string) > $context) {
        $context = strlen($string);

function max_len_finalize(&$context) 
    return $context;

sqlite_create_aggregate($db, 'max_len', 'max_len_step', 'max_len_finalize');

var_dump(sqlite_array_query($db, 'SELECT max_len(a) from strings'));


Last updated: Tue, 19 Sep 2006