SQLite Functions
PHP Manual

sqlite_udf_decode_binary

Decode binary data passed as parameters to an UDF

Description

string sqlite_udf_decode_binary ( string $data )

Decodes binary data passed as parameters to a UDF.

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.

Parameters

data

The encoded data that will be decoded, data that was applied by either sqlite_udf_encode_binary or sqlite_escape_string.

Return Values

The decoded string.

Examples

Example #1 binary-safe max_length aggregation function example

<?php
$data = array(
   'one',
   'two',
   'three',
   'four',
   'five',
   'six',
   'seven',
   'eight',
   'nine',
   'ten',
   );
$db = sqlite_open(':memory:');
sqlite_query($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'));

?>

See Also

  • sqlite_udf_encode_binary
  • sqlite_create_function
  • sqlite_create_aggregate