SQLite3::createFunction

    (PHP 5 >= 5.3.0, PHP 7, PHP 8)

    SQLite3::createFunction — Registers a PHP function for use as an SQL scalar function

    Description

    public SQLite3::createFunction(
        string $name,
        callable $callback,
        int $argCount = -1,
        int $flags = 0
    ): bool

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

    Parameters

    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.

    This function need to be defined as:

    callback(mixed $value, mixed ...$values): mixed
    value

    The first argument passed to the SQL function.

    values

    Further arguments passed to the SQL function.

    argCount

    The number of arguments that the SQL function takes. If this parameter is -1, then the SQL function may take any number of arguments.

    flags

    A bitwise conjunction of flags. Currently, only SQLITE3_DETERMINISTIC is supported, which specifies that the function always returns the same result given the same inputs within a single SQL statement.

    Return Values

    Returns true upon successful creation of the function, false on failure.

    Changelog

    Version Description
    7.1.4 The flags parameter has been added.

    Examples

    Example #1 SQLite3::createFunction() example

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

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

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

    The above example will output something similar to:

    string(32) "098f6bcd4621d373cade4e832627b4f6"

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    User Contributed Notes 2 notes

    up
    9
    koalay at gmail dot com
    14 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)"    );

    ?>
    up
    -1
    bohwaz
    12 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).
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