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php实现mysql

2026-04-02 20:26:40PHP

PHP 连接 MySQL 的基本方法

使用 mysqli 扩展连接 MySQL 数据库。确保 PHP 已安装 mysqli 扩展，MySQL 服务正常运行。

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "myDB";

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully";
?>

执行 SQL 查询

通过 query 方法执行 SQL 语句，处理查询结果。

$sql = "SELECT id, name FROM users";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
    while($row = $result->fetch_assoc()) {
        echo "id: " . $row["id"]. " - Name: " . $row["name"]. "<br>";
    }
} else {
    echo "0 results";
}

插入数据到 MySQL

使用预处理语句防止 SQL 注入，插入数据更安全。

$stmt = $conn->prepare("INSERT INTO users (name, email) VALUES (?, ?)");
$stmt->bind_param("ss", $name, $email);

$name = "John Doe";
$email = "john@example.com";
$stmt->execute();

echo "New records created successfully";
$stmt->close();

更新 MySQL 数据

通过预处理语句更新现有记录。

$stmt = $conn->prepare("UPDATE users SET name=? WHERE id=?");
$stmt->bind_param("si", $name, $id);

$name = "Jane Doe";
$id = 1;
$stmt->execute();

echo "Record updated successfully";
$stmt->close();

关闭数据库连接

操作完成后关闭连接释放资源。

$conn->close();

错误处理

使用 try-catch 块捕获异常，提高代码健壮性。

try {
    $conn = new mysqli($servername, $username, $password, $dbname);
    if ($conn->connect_error) {
        throw new Exception("Connection failed: " . $conn->connect_error);
    }
} catch (Exception $e) {
    echo "Error: " . $e->getMessage();
}

使用 PDO 连接 MySQL

PDO 提供统一的接口支持多种数据库，更灵活。

php实现mysql

try {
    $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo "Connected successfully"; 
} catch(PDOException $e) {
    echo "Connection failed: " . $e->getMessage();
}