groups looks like this '1,2,3,999'
<?php
/**
* int strpos ( string $haystack , mixed $needle [, int $offset = 0 ] )
*/
$dbUser = new PDO('sqlite:'.ROOT.'/var/db/users.db3');
$dbUser->sqliteCreateFunction('strpos', 'strpos', 2);
$sql = 'SELECT username FROM users WHERE strpos(groups,",2,");';
$rows = $dbUser->query($sql)->fetchAll(PDO::FETCH_ASSOC);
print_r($rows);
?>
PDO::sqliteCreateFunction
(PHP 5 >= 5.1.0, PHP 7, PHP 8, PECL pdo_sqlite >= 1.0.0)
PDO::sqliteCreateFunction — Registers a User Defined Function for use in SQL statements
Descrizione
public PDO::sqliteCreateFunction(
string
callable
int
int
): bool
string
$function_name,callable
$callback,int
$num_args = -1,int
$flags = 0): bool
Avviso
Questa funzione è SPERIMENTALE. Ovvero, il comportamento di questa funzione, il nome di questa funzione, in definitiva tutto ciò che è documentato qui può cambiare nei futuri rilasci del PHP senza preavviso. Siete avvisati, l'uso di questa funzione è a vostro rischio.
This method allows you to register a PHP function with SQLite as an UDF (User Defined Function), so that it can be called from within your SQL statements.
The UDF can be used in any SQL statement that can call functions, such as SELECT and UPDATE statements and also in triggers.
Elenco dei parametri
-
function_name -
The name of the function used in SQL statements.
-
callback -
Callback function to handle the defined SQL function.
Nota: Callback functions should return a type understood by SQLite (i.e. scalar type).
This function need to be defined as:
-
value -
The first argument passed to the SQL function.
-
values -
Further arguments passed to the SQL function.
-
-
num_args -
The number of arguments that the SQL function takes. If this parameter is
-1, then the SQL function may take any number of arguments. -
flags -
A bitwise conjunction of flags. Currently, only
PDO::SQLITE_DETERMINISTICis supported, which specifies that the function always returns the same result given the same inputs within a single SQL statement.
Valori restituiti
Restituisce true in caso di successo, false in caso di fallimento.
Log delle modifiche
| Versione | Descrizione |
|---|---|
| 7.1.4 |
The flags parameter has been added.
|
Esempi
Example #1 PDO::sqliteCreateFunction() example
<?php
function md5_and_reverse($string)
{
return strrev(md5($string));
}
$db = new PDO('sqlite:sqlitedb');
$db->sqliteCreateFunction('md5rev', 'md5_and_reverse', 1);
$rows = $db->query('SELECT md5rev(filename) FROM files')->fetchAll();
?>
In this example, we have a function that calculates the md5 sum of a
string, and then reverses it. When the SQL statement executes, it
returns the value of the filename transformed by our function. The data
returned in $rows contains the processed result.
The beauty of this technique is that you do not need to process the result using a foreach loop after you have queried for the data.
Suggerimento
You can use PDO::sqliteCreateFunction and PDO::sqliteCreateAggregate to override SQLite native SQL functions.
add a note
User Contributed Notes 1 note
RoboTamer ¶
12 years ago
