(PHP 5 >= 5.3.0, PHP 7, PHP 8)
SQLite3::createFunction — Registers a PHP function for use as an SQL scalar function
$name,$callback,$argCount = -1,$flags = 0Registers a PHP function or user-defined function for use as an SQL scalar function for use within SQL statements.
nameName of the SQL function to be created or redefined.
callbackThe 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:
valueThe first argument passed to the SQL function.
valuesFurther 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.
| Version | Description |
|---|---|
| 7.1.4 |
The flags parameter has been added.
|
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"
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)");?>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:<?phpsetlocale(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:<?phpfunction 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).