Евгений

$statment->bindParam(":login", $login);
  $statment->bindParam(":login", $password);

$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

UPDATE Prod SET result = w*eft/(SELECT Forc.rft * (1 + Forc.cos / 10) from Forc where Forc.id=Prod.id)

<?php
$limit = 10000;
$offset = 0;
do {
$data = $db->query("SELECT * FROM `tbl` ORDER BY `id` ASC LIMIT $limit OFFSET $offset")->fetchAll();
$offset += count($data); 
}
while(count($data));

SELECT * FROM rel GROUP BY CONCAT(us1, '|', us2, '|', rel)

$sphinx = new SphinxClient();
$sphinx->SetServer('127.0.0.1', 9312);
$sphinx->SetMatchMode(SPH_MATCH_FULLSCAN);
$sphinx->SetFilter('tag', array(1,2,3));
$result = $sphinx->Query('', '*');