PHP 7.2.8 Released

sqlite_udf_decode_binary

(PHP 5 < 5.4.0, PECL sqlite >= 1.0.0)

sqlite_udf_decode_binaryDecode 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

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User Contributed Notes 1 note

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1
BenWa
23 days ago
I had to migrate an existing SQLITE2 db with UDF encoded fields. SQLITE3 does not support sqlite_udf_decode_binary. So I wrote a replacement for the migration.

    function sqlite_udf_decode_binary($in){
      if ( substr($in,0,1)==chr(1) ) {
        $n=strlen($in);
        $e=ord(substr($in,1,1));
        $i=2 ;
        while($i<$n){
            $x = ord(substr($in,$i,1)) ;
            if ($x==1) {
                $i++;
                $x = ord(substr($in,$i,1)) - 1 ;
            }
            $out .= chr($x+$e) ;
            $i++;
        }
         
      } else {
          $out = $in ;
      }
      return $out ;
    }
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