MySQL query optimization - php

Question

$res (array)-> (count 50 (!) )
Example:
(
[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
)
}
PHP code:
$massquery = '';
foreach($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);
It turns out 50 requests "SELECT" to the database, which is very bad = (
How can I optimize this code?
From answers:
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
How do I INSERT those songs that are not yet in the database?
Sorry for bad english

Answer 1

You want to insert new records only if no other record with the tuple (artistname,songname,server) (already) exists.
If you create a unique index for these three fields MySQL won't insert a doublet. Then you can either use something like
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)
or a prepared statement, e.g.
$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";
}
prints
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
The first three records have not been duplicated.

Answer 2

Create a single select for all the relevant cases like this, and verify the results by means of 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

The select query you wrote can't be inside the foreach, or of course it'll query each time. Turn your $res into a long WHERE clause:
$sql = "SELECT `artistname`,`songname`,`server` FROM `music` WHERE FALSE ";
foreach($res as $value)
{
// ...
$sql .= "OR (`artistname`='".$value['artistname']."' AND `songname`='".$value['songname']."' AND `server`='".$value['server'].")";
}
and then run that query against the database and build your INSERT query.