MySQL optimisation des requêtes

Question

$ res (array) -> (compter 50()!) Exemple:

(
    [1] => Array 
     (
      [artistname] => Lady GaGa 
      [songname] => Love Games 
      [duration] => 3:31 
      [url] => 7e91a5ca16ae 
      [server] => 3 
     ) 

    [2] => Array 
     (
      [artistname] => DJ Layla 
      [songname] => Single Lady 
      [duration] => 3:20 
      [url] => f0906a3087eb 
      [server] => 3 
     ) 

    [3] => Array 
     (
      [artistname] => Lady Gaga 
      [songname] => Bad Romance (Bimbo Jones Clean Radio Remix) 
      [duration] => 3:59 
      [url] => 36e77d5a80357 
      [server] => 3 
     ) 
} 

Code PHP:

$massquery = ''; 
foreach($res as $value) 
{ 
    if(!get_magic_quotes_gpc()) 
    { 
     $value['artistname'] = mysql_escape_string($value['artistname']); 
     $value['songname']  = mysql_escape_string($value['songname']); 
     $value['duration']  = mysql_escape_string($value['duration']); 
     $value['url']   = mysql_escape_string($value['url']); 
     $value['server']  = mysql_escape_string($value['server']); 
    } 

    $value['artistname'] = trim($value['artistname']); 
    $value['songname']  = trim($value['songname']); 
    $value['duration']  = trim($value['duration']); 
    $value['url']   = trim($value['url']); 
    $value['server']  = trim($value['server']); 

    $sh  = mysql_query("SELECT `artistname`,`songname`,`server` FROM `music` WHERE `artistname`='".$value['artistname']."' AMD `songname`='".$value['songname']."' AND `server`='".$value['server']."' LIMIT 1"); 
    if(!mysql_num_rows($sh)) 
    { 
     $massquery .= '("'.$value['artistname'].'", "'.$value['songname'].'", "'.$value['duration'].'", "'.$value['url'].'", "'.$value['server'].'"),'; 
    } 
} 

if(!empty($massquery)) 
{ 
    $massquery = substr($massquery, 0, -1); 
    $query  = mysql_query('INSERT INTO `music` (`artistname`, `songname`, `duration`, `url`, `server`) VALUES '.$massquery); 
} 
mysql_close($mysql); 

Il se trouve 50 demandes "SELECT" au base de données, ce qui est très mauvais = ( Comment optimiser ce code

De réponses:

CREATE TABLE `music` (
    `id` int(50) NOT NULL auto_increment, 
    `artistname` varchar(50) NOT NULL, 
    `songname` varchar(50) NOT NULL, 
    `duration` varchar(6) NOT NULL, 
    `url` varchar(255) NOT NULL, 
    `server` int(5) NOT NULL, 
    PRIMARY KEY (`id`), 
    KEY `artistname` (`artistname`,`songname`,`server`) 
) ENGINE=MyISAM DEFAULT CHARSET=utf8; 

INSERT INTO `music` VALUES ('test', 'btest', 1); 

...

SELECT `artistname` , `songname` , `server` 
FROM `music` 
WHERE FALSE 
OR (
`artistname` = 'test' 
AND `songname` = 'btest' 
AND `server` = '1' 
) 
OR (
`artistname` = 'sas' 
AND `songname` = 'asf' 
AND `server` = '1' 
) 
LIMIT 0 , 30 

Comment insérer ces chansons qui ne sont pas encore dans la base de données? Désolé pour un mauvais anglais

Answer 1

Vous ne voulez insérer de nouveaux enregistrements que si aucun autre enregistrement avec le tuple (nom de l'artiste, nom de la chanson, serveur) n'existe déjà.
Si vous create a unique index pour ces trois champs MySQL n'insèrera pas un doublet. Ensuite, vous pouvez soit utiliser quelque chose comme

INSERT IGNORE INTO 
    tablename 
    (a,b,c,x,y,z) 
VALUES 
    (1,2,3,4,5,6), 
    (7,8,9,10,11,12), 
    ... 
    (95,96,97,98,99,100) 

ou un prepared statement, par exemple

$pdo = new PDO("mysql:host=localhost;dbname=test", 'localonly', 'localonly'); 
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 

/* test table */ 
$pdo->exec(' 
    CREATE TEMPORARY TABLE foo (
     id int auto_increment, 
     artistname varchar(64) not null, 
     songname varchar(64) not null, 
     duration varchar(16) not null, 
     url varchar(64) not null, 
     server int not null, 
     primary key(id), 
     unique key (artistname,songname,server) 
    ) 
'); 

$data = array(
    array(':artistname' => 'Lady GaGa', ':songname' => 'Love Games', ':duration' => '3:31', ':url' => '7e91a5ca16ae', ':server' => 3), 
    array(':artistname' => 'DJ Layla', ':songname' => 'Single Lady', ':duration' => '3:20', ':url' => 'f0906a3087eb', ':server' => 3), 
    array(':artistname' => 'Lady Gaga', ':songname' => 'Bad Romance (Bimbo Jones Clean Radio Remix)', ':duration' => '3:59', ':url' => '36e77d5a80357', ':server' => 3) 
); 


/* the "actual" test script */ 
$stmt = $pdo->prepare(' 
    INSERT IGNORE INTO 
     foo 
     (duration, artistname, songname, server, url) 
    VALUES 
     (:duration, :artistname, :songname, :server, :url) 
'); 
// first run, all three records should be inserted 
foreach($data as $params) { 
    $stmt->execute($params); 
} 

// second run 
// same artist/songname, different server 
$newData = $data[0]; $newData[':server'] = 4; 
$data[] = $newData; 
// and a completly new record 
$data[] = array(':artistname' => 'xyz', ':songname' => 'The ABC song', ':duration' => '2:31', ':url' => 'whatever', ':server' => 2); 
// again insert all records (including the three that have already been inserted) 
foreach($data as $params) { 
    $stmt->execute($params); 
} 

/* fetch all records */ 
foreach($pdo->query('SELECT * FROM foo', PDO::FETCH_NUM) as $row) { 
    echo join(', ', $row), "\n"; 
} 

impressions

1, Lady GaGa, Love Games, 3:31, 7e91a5ca16ae, 3 
2, DJ Layla, Single Lady, 3:20, f0906a3087eb, 3 
3, Lady Gaga, Bad Romance (Bimbo Jones Clean Radio Remix), 3:59, 36e77d5a80357, 3 
4, Lady GaGa, Love Games, 3:31, 7e91a5ca16ae, 4 
5, xyz, The ABC song, 2:31, whatever, 2 

Les trois premiers enregistrements ne sont pas dupliqués.

Answer 2

Créer une Unique.Sélectionnez pour tous les cas pertinents comme celui-ci, et vérifier les résultats au moyen de PHP:

$sh = "SELECT `artistname`,`songname`,`server` FROM `music` WHERE "; 
$pq = "" 
foreach($res as $value) 
{ 
if(!get_magic_quotes_gpc()) 
{ 
    $value['artistname'] = mysql_escape_string($value['artistname']); 
    $value['songname']  = mysql_escape_string($value['songname']); 
    $value['duration']  = mysql_escape_string($value['duration']); 
    $value['url']   = mysql_escape_string($value['url']); 
    $value['server']  = mysql_escape_string($value['server']); 
} 

$value['artistname'] = trim($value['artistname']); 
$value['songname']  = trim($value['songname']); 
$value['duration']  = trim($value['duration']); 
$value['url']   = trim($value['url']); 
$value['server']  = trim($value['server']); 

$sh .= $pq . `(artistname`='".$value['artistname']."' AMD `songname`='".$value['songname']."' AND `server`='".$value['server']."')"); 
$pq = " OR "; 
} 

$res = mysql_query($sh); 

Answer 3

La requête de sélection que vous avez écrit ne peut pas être à l'intérieur du foreach, ou bien sûr, il » ll question chaque fois. Transformez vos $ res en une longue clause WHERE:

$sql = "SELECT `artistname`,`songname`,`server` FROM `music` WHERE FALSE "; 
foreach($res as $value) 
{ 
    // ... 

    $sql .= "OR (`artistname`='".$value['artistname']."' AND `songname`='".$value['songname']."' AND `server`='".$value['server'].")"; 
} 

puis exécutez cette requête contre la base de données et de construire votre requête INSERT.