SQLite3::createAggregate

(PHP 5 >= 5.3.0, PHP 7)

SQLite3::createAggregate — Registers a PHP function for use as an SQL aggregate function

Description

public bool SQLite3::createAggregate ( string $name , mixed $step_callback , mixed $final_callback [, int $argument_count = -1 ] )

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

Parameters

name: Name of the SQL aggregate to be created or redefined.
step_callback: The name of a PHP function or user-defined function to apply as a callback for every item in the aggregate.
final_callback: The name of a PHP function or user-defined function to apply as a callback at the end of the aggregate data.
argument_count: The number of arguments that the SQL aggregate takes. If this parameter is negative, then the SQL aggregate may take any number of arguments.

Return Values

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

User Contributed Notes

sukmaagungsaputra at gmail dot com

1 year ago


Lacks of example, right?
Let's try to give to SQlite3 the capability like ones of MySQL's
- REGEXP operator,
- MD5 function, and
- GROUP_CONCAT aggregate function

$db = new SQLite3($filename);
$db->createFunction('regexp', function ($a,$b) { return preg_match("/$a/i", $b); });
$db->createFunction('md5', function ($a) { return md5($a); });
$db->createAggregate ('group_concat',
            function(&$context, $rownumber, $str) { $context[]=$str; return $context; },
            function(&$context) {return implode(",", (array) $context); });