How to connect to database in PHP7

Recommended (free): PHP7

* Already in PHP7 The mysql library is abolished, so you can only use mysqli and PDO

##mysqli object-oriented style

<?php$serve = &#39;localhost:3306&#39;;$username = &#39;root&#39;;$password = &#39;admin123&#39;;$dbname = &#39;examples&#39;;$mysqli = new Mysqli($serve,$username,$password,$dbname);if($mysqli->connect_error){
	die(&#39;connect error:&#39;.$mysqli->connect_errno);}$mysqli->set_charset(&#39;UTF-8&#39;); // 设置数据库字符集$result = $mysqli->query(&#39;select * from customers&#39;);$data = $result->fetch_all(); // 从结果集中获取所有数据print_r($data);

 ?>

mysqliProcess-oriented style

<?php$serve = &#39;localhost:3306&#39;;$username = &#39;root&#39;;$password = &#39;admin123&#39;;$dbname = &#39;examples&#39;;$link = mysqli_connect($serve,$username,$password,$dbname);mysqli_set_charset($link,&#39;UTF-8&#39;); // 设置数据库字符集$result = mysqli_query($link,&#39;select * from customers&#39;);$data = mysqli_fetch_all($result); // 从结果集中获取所有数据print_r($data);

 ?>

PDO connection database

<?php$serve = &#39;mysql:host=localhost:3306;dbname=examples;charset=utf8&#39;;$username = &#39;root&#39;;$password = &#39;admin123&#39;;try{ // PDO连接数据库若错误则会抛出一个PDOException异常
	$PDO = new PDO($serve,$username,$password);
	$result = $PDO->query(&#39;select * from customers&#39;);
	$data = $result->fetchAll(PDO::FETCH_ASSOC); // PDO::FETCH_ASSOC表示将对应结果集中的每一行作为一个由列名索引的数组返回
	print_r($data);} catch (PDOException $error){
	echo &#39;connect failed:&#39;.$error->getMessage();}

 ?>

You can use PDO or mysqli to connect to mysql, but it is more recommended to use PDO to connect to the database, because PDO supports 12 different database drivers. mysqli only supports mysql, and PDO has higher performance

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