* 在PHP7中已经废除了mysql库了，则只能使用mysqli及PDO
mysqli面向对象风格
<?php
$serve = 'localhost:3306';
$username = 'root';
$password = 'admin123';
$dbname = 'examples';
$mysqli = new Mysqli($serve,$username,$password,$dbname);
if($mysqli->connect_error){
die('connect error:'.$mysqli->connect_errno);
}
$mysqli->set_charset('UTF-8');
$result = $mysqli->query('select * from customers');
$data = $result->fetch_all();
print_r($data);
?>
mysqli面向过程风格
<?php
$serve = 'localhost:3306';
$username = 'root';
$password = 'admin123';
$dbname = 'examples';
$link = mysqli_connect($serve,$username,$password,$dbname);
mysqli_set_charset($link,'UTF-8');
$result = mysqli_query($link,'select * from customers');
$data = mysqli_fetch_all($result);
print_r($data);
?>
PDO连接数据库
<?php
$serve = 'mysql:host=localhost:3306;dbname=examples;charset=utf8';
$username = 'root';
$password = 'admin123';
try{
$PDO = new PDO($serve,$username,$password);
$result = $PDO->query('select * from customers');
$data = $result->fetchAll(PDO::FETCH_ASSOC);
print_r($data);
} catch (PDOException $error){
echo 'connect failed:'.$error->getMessage();
}
?>
使用PDO或mysqli都可以连接mysql，但更推荐使用PDO连接数据库，因为PDO支持12种不同的数据库驱动程序，mysqli只支持mysql，而且PDO性能更高
