SQLite3::createFunction

(PHP 5 >= 5.3.0)

SQLite3::createFunctionRegisters a PHP function for use as an SQL scalar function

Descrição

public bool SQLite3::createFunction ( string $name , mixed $callback [, int $argument_count = -1 ] )

Registers a PHP function or user-defined function for use as an SQL scalar function for use within SQL statements.

Parâmetros

name

Name of the SQL function to be created or redefined.

callback

The name of a PHP function or user-defined function to apply as a callback, defining the behavior of the SQL function.

argument_count

The number of arguments that the SQL function takes. If this parameter is negative, then the SQL function may take any number of arguments.

Valor Retornado

Returns TRUE upon successful creation of the function, FALSE on failure.

Exemplos

Exemplo #1 SQLite3::createFunction() example

<?php
function my_udf_md5($string) {
    return 
md5($string);
}

$db = new SQLite3('mysqlitedb.db');
$db->createFunction('my_udf_md5''my_udf_md5');

var_dump($db->querySingle('SELECT my_udf_md5("test")'));
?>

O exemplo acima irá imprimir algo similar à:

string(32) "098f6bcd4621d373cade4e832627b4f6"

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User Contributed Notes 2 notes

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0
bohwaz
2 years ago
In PHP 5.4 there will be a createCollation method to use your custom collation method, to be able to sort datasets using unicode, like this:

<?php
setlocale
(LC_COLLATE, 'fr_FR.UTF-8');
$db->createCollation('PHP_COLLATE', 'strcoll');

$db->query('SELECT * FROM my_table ORDER BY name COLLATE PHP_COLLATE;');
?>

But until this cool feature becomes available, you'll have to do some tricks, like this for french:

<?php
function sqlite3_to_ascii($str, $charset = 'UTF-8')
{
   
// Don't process empty strings
   
if (!trim($str))
        return
$str;

   
// We only process non-ascii strings
   
if (preg_match('!^[[:ascii:]]+$!', $str))
        return
$str;

   
$str = htmlentities($str, ENT_NOQUOTES, $charset);

   
$str = preg_replace('#&([A-za-z])(?:acute|cedil|circ|grave|orn|ring|slash|th|tilde|uml);#', '\1', $str);
   
$str = preg_replace('#&([A-za-z]{2})(?:lig);#', '\1', $str);
   
$str = preg_replace('#&[^;]+;#', '', $str);

    return
$str;
}

$db->createFunction('to_ascii', 'sqlite3_to_ascii', 1);
$res = $db->query('SELECT * FROM test ORDER BY to_ascii(text);');
?>

This will convert non-ascii characters to ascii ones before collation. In fact this won't work with non-latin languages, but for latin-languages it's better than nothing.

Please note that this will slow down about 1.8 times the query (tested on a 10.000 rows table).
up
0
koalay at gmail dot com
3 years ago
Since regular expression is not supported by default SQLite, we can create a user function to do the job.

<?php

$db
= new SQLite3("database.sqlit3", 0666);

// create a function named "preg_match"
// with the php core function "preg_match"
if ($db->createFunction("preg_match", "preg_match", 2) === FALSE)
  exit(
"Failed creating function\n");

// this query will then works as expected
$result = $db->query("SELECT * FROM table1 WHERE
  preg_match('/^(apple|orange)$/', variable1)"
);

?>
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