SQLite3::createFunction

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

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

说明

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.

参数

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.

返回值

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

更新日志

版本	说明
7.1.4	The `flags` parameter has been added.

范例

示例 #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")'));
?>

以上例程的输出类似于：

string(32) "098f6bcd4621d373cade4e832627b4f6"

add a note

User Contributed Notes 2 notes

down

koalay at gmail dot com ¶

12 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)");

?>

down

-1

bohwaz ¶

10 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).

add a note

官方地址：https://www.php.net/manual/en/sqlite3.createfunction.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络 JAVA NoSQL 数据库面试 C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet ADORecordSet对象 adodb手册 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 opcache预加载 Composer的Packagist资源 mysql面试题 [鸟哥]PHP FFI详解 - 一种全新的PHP扩展方式 PHP7添加redis扩展 PHP mkdir()写出来的权限与mode值不符合 Packagist / Composer 中国全量镜像 php中几种注释规范利用php soap实现web service PHP获取指定函数定义在哪个文件中及行号

略微加速

PHP官方手册 - 互联网笔记

SQLite3::createFunction

说明

参数

返回值

更新日志

范例

User Contributed Notes 2 notes