php教程：操作MySQL数据库之读取数据

た入场券 2023-10-16 16:18 50阅读 0赞

#### [从 MySQL 数据库读取数据 ][MySQL _][目录][Link 1] ####

##### [MySQLi ][MySQLi][目录][Link 1] #####

$sql = "SELECT id, firstname, lastname FROM MyGuests";
    $result = $conn->query($sql);
     
    if ($result->num_rows > 0) {
        // 输出数据
        while($row = $result->fetch_assoc()) {
            echo "id: " . $row["id"]. " - Name: " . $row["firstname"]. " " . $row["lastname"]. "<br>";
        }
    } else {
        echo "0 结果";
    }
    $conn->close();

##### [PDO(+ 预处理) ][PDO_ _][目录][Link 1] #####

$stmt = $conn->prepare("SELECT id, firstname, lastname FROM MyGuests"); 
    $stmt->execute();
     
    // 设置结果集为关联数组
    $result = $stmt->setFetchMode(PDO::FETCH_ASSOC); 
    foreach(new TableRows(new RecursiveArrayIterator($stmt->fetchAll())) as $k=>$v) { 
    	echo $v;
    }
        
    
    // TableRows类，用于关联数组的表格形式输出
    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";
        } 
    }

参考资料：

(1) [在 Linux 命令行中使用和执行 PHP 代码][Linux _ PHP]

[MySQL _]: https://github.com/Ming-Lian/Memo/blob/master/%E5%AD%A6%E4%B9%A0%E7%AC%94%E8%AE%B0%EF%BC%9APHP%E4%B8%80%E5%91%A8%E9%80%9F%E6%88%90.md#%E4%BB%8E-mysql-%E6%95%B0%E6%8D%AE%E5%BA%93%E8%AF%BB%E5%8F%96%E6%95%B0%E6%8D%AE-%E7%9B%AE%E5%BD%95
[Link 1]: https://github.com/Ming-Lian/Memo/blob/master/%E5%AD%A6%E4%B9%A0%E7%AC%94%E8%AE%B0%EF%BC%9APHP%E4%B8%80%E5%91%A8%E9%80%9F%E6%88%90.md#content
[MySQLi]: https://github.com/Ming-Lian/Memo/blob/master/%E5%AD%A6%E4%B9%A0%E7%AC%94%E8%AE%B0%EF%BC%9APHP%E4%B8%80%E5%91%A8%E9%80%9F%E6%88%90.md#mysqli-%E7%9B%AE%E5%BD%95-3
[PDO_ _]: https://github.com/Ming-Lian/Memo/blob/master/%E5%AD%A6%E4%B9%A0%E7%AC%94%E8%AE%B0%EF%BC%9APHP%E4%B8%80%E5%91%A8%E9%80%9F%E6%88%90.md#pdo-%E9%A2%84%E5%A4%84%E7%90%86-%E7%9B%AE%E5%BD%95
[Linux _ PHP]: https://www.cnblogs.com/luoyunshu/p/4819923.html