PHP7连接MySQL数据库有两种方法

 1<?php
 2$servername = "localhost";
 3$username = "username";
 4$password = "password";
 5$conn = new mysqli($servername, $username, $password);
 6if ($conn->connect_error) {
 7    die("连接失败: " . $conn->connect_error);
 8}
 9echo "连接成功";
10$conn->close(); 
11?>

 1<?php
 2$servername = "localhost";
 3$username = "username";
 4$password = "password";
 5$dbname = "web_test"; //数据库名
 6try {
 7    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
 8    echo "连接成功";
 9}
10catch(PDOException $e)
11{
12     
13echo $e->getMessage();
14 
15$conn = null; //关闭连接 
16?>