PHP怎么连接MySQL数据库并获取数据

要连接MySQL数据库并获取数据，你可以使用PHP中的mysqli扩展或PDO扩展。下面是一个示例代码，演示如何连接MySQL数据库并获取数据：

使用mysqli扩展：

// 连接数据库$servername = "localhost";$username = "username";$password = "password";$dbname = "database_name";$conn = new mysqli($servername, $username, $password, $dbname);// 检查连接是否成功if ($conn->connect_error) {    die("Connection failed: " . $conn->connect_error);}// 查询数据$sql = "SELECT * FROM table_name";$result = $conn->query($sql);// 输出查询结果if ($result->num_rows > 0) {    while($row = $result->fetch_assoc()) {        echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";    }} else {    echo "0 results";}// 关闭连接$conn->close();

使用PDO扩展：

// 连接数据库$servername = "localhost";$username = "username";$password = "password";$dbname = "database_name";try {    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);        // 查询数据    $stmt = $conn->prepare("SELECT * FROM table_name");    $stmt->execute();        // 输出查询结果    $result = $stmt->fetchAll();    foreach($result as $row) {        echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";    }} catch(PDOException $e) {    echo "Connection failed: " . $e->getMessage();}// 关闭连接$conn = null;

以上是使用mysqli扩展和PDO扩展连接MySQL数据库并获取数据的示例代码。你可以根据自己的实际情况选择其中一种来使用。