# PHP MySQL 讀取數據 ## 從 MySQL 數據庫讀取數據 SELECT 語句用于從數據表中讀取數據: ``` SELECT column_name(s) FROM table_name ``` 如需學習更多關于 SQL 的知識，請訪問我們的 [SQL 教程](/sql/sql-tutorial.html)。 以下實例中我們從表 MyGuests 讀取了 id, firstname 和 lastname 列的數據并顯示在頁面上： ## 實例 (MySQLi - 面向對象) ``` <?php $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "myDB"; // 創建連接 $conn = new mysqli($servername, $username, $password, $dbname); // 檢測連接 if ($conn->connect_error) { ??? die("Connection failed: " . $conn->connect_error); } $sql = "SELECT id, firstname, lastname FROM MyGuests"; $result = $conn->query($sql); if ($result->num_rows > 0) { ??? // 輸出每行數據 ??? while($row = $result->fetch_assoc()) { ??????? echo "<br> id: ". $row["id"]. " - Name: ". $row["firstname"]. " " . $row["lastname"]; ??? } } else { ??? echo "0 results"; } $conn->close(); ?> ``` 以下實例讀取了 MyGuests 表的所有記錄并顯示在 HTML 表格中： ## 實例 (PDO) ``` <?php echo "<table style='border: solid 1px black;'>"; echo "<tr><th>Id</th><th>Firstname</th><th>Lastname</th><th>Email</th><th>Reg date</th></tr>"; class TableRows extends RecursiveIteratorIterator { ??? function __construct($it) { ??????? parent::__construct($it, self::LEAVES_ONLY); ??? } ??? function current() { ??????? return "<td style='width: 150px; border: 1px solid black;'>" . parent::current(). "</td>"; ??? } ??? function beginChildren() { ??????? echo "<tr>"; ??? } ??? function endChildren() { ??????? echo "</tr>" . "\n"; ??? } } $servername = "localhost"; $username = "username"; $password = "password"; $dbname = "myDBPDO"; try { ??? $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password); ??? $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); ??? $stmt = $conn->prepare("SELECT * FROM MyGuests"); ??? $stmt->execute(); ??? // 設置結果集為關聯數組 ??? $result = $stmt->setFetchMode(PDO::FETCH_ASSOC); ??? foreach(new TableRows(new RecursiveArrayIterator($stmt->fetchAll())) as $k=>$v) { ??????? echo $v; ??? } ??? $dsn = null; ??? } catch(PDOException $e) ??? { ??? echo "Error: " . $e->getMessage(); ??? } $conn = null; echo "</table>"; ?> ```