1. php 连接数据库

header("Content-type:text/html; charset=utf8");
$servername = "localhost";
$username = "root";
$password = "root";
$dbTable = "dvwa";

$conn = mysqli_connect($servername, $username, $password, $dbTable);


if(!$conn)
    die("mysql连接失败：".mysqli_connect_error());

echo "mysql连接成功！";

2. php 查询数据库

$result = mysqli_query($conn, "select * from Student;");  // 获得结果
$data = mysqli_fetch_array($result)                       // 以数组的方式取出数据

3. php 实现增删改

$result = mysqli_query($conn, $sql);
$affected_row = mysqli_affected_rows($conn);    // 影响的数据条数，整数
if($affected_row) {
	echo 'success';
} else {
	echo 'error';
}