PHP : Function Reference : SQLite Functions (PDO_SQLITE) : PDO->sqliteCreateAggregate() PHP Examples Tutorials References

Example 2341. max_length aggregation function example

<?php

$data = array(

   'one',

   'two',

   'three',

   'four',

   'five',

   'six',

   'seven',

   'eight',

   'nine',

   'ten',

   );
$db = new PDO('sqlite::memory:');
$db->exec("CREATE TABLE strings(a)");
$insert = $db->prepare('INSERT INTO strings VALUES (?)');

foreach ($data as $str) {

    $insert->execute(array($str));

}
$insert = null;


function max_len_step(&$context, $rownumber, $string) 

{

    if (strlen($string) > $context) {

        $context = strlen($string);

    }

}


function max_len_finalize(&$context, $rownumber) 

{

    return $context;

}

$db->sqliteCreateAggregate('max_len', 'max_len_step', 'max_len_finalize');

var_dump($db->query('SELECT max_len(a) from strings')->fetchAll());

?>

PDO->sqliteCreateAggregate()

Registers an aggregating User Defined Function for use in SQL statements ()

Example 2341. max_length aggregation function example

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