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php实现增删改查

2026-02-13 12:12:26PHP

PHP 实现增删改查操作

数据库连接

使用 PDO（PHP Data Objects）连接数据库，确保安全性并支持多种数据库类型。示例代码：

$host = 'localhost';
$dbname = 'your_database';
$username = 'your_username';
$password = 'your_password';

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

创建数据（Create）

通过 SQL 的 INSERT 语句添加数据，使用预处理语句防止 SQL 注入。

php实现增删改查

$name = 'John Doe';
$email = 'john@example.com';

$sql = "INSERT INTO users (name, email) VALUES (:name, :email)";
$stmt = $pdo->prepare($sql);
$stmt->bindParam(':name', $name);
$stmt->bindParam(':email', $email);

if ($stmt->execute()) {
    echo "Record created successfully";
} else {
    echo "Error creating record";
}

读取数据（Read）

使用 SELECT 语句查询数据，并通过 fetchAll 获取结果集。

$sql = "SELECT id, name, email FROM users";
$stmt = $pdo->query($sql);
$users = $stmt->fetchAll(PDO::FETCH_ASSOC);

foreach ($users as $user) {
    echo "ID: " . $user['id'] . ", Name: " . $user['name'] . ", Email: " . $user['email'] . "<br>";
}

更新数据（Update）

通过 UPDATE 语句修改数据，绑定参数确保安全性。

php实现增删改查

$id = 1;
$newEmail = 'new_email@example.com';

$sql = "UPDATE users SET email = :email WHERE id = :id";
$stmt = $pdo->prepare($sql);
$stmt->bindParam(':email', $newEmail);
$stmt->bindParam(':id', $id);

if ($stmt->execute()) {
    echo "Record updated successfully";
} else {
    echo "Error updating record";
}

删除数据（Delete）

使用 DELETE 语句移除数据，通过参数绑定避免注入风险。

$id = 1;

$sql = "DELETE FROM users WHERE id = :id";
$stmt = $pdo->prepare($sql);
$stmt->bindParam(':id', $id);

if ($stmt->execute()) {
    echo "Record deleted successfully";
} else {
    echo "Error deleting record";
}

完整示例

以下是一个完整的增删改查示例，包含表单处理和数据库操作：

// 数据库连接
$pdo = new PDO("mysql:host=localhost;dbname=your_database", "username", "password");

// 处理表单提交
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    if (isset($_POST['create'])) {
        $name = $_POST['name'];
        $email = $_POST['email'];
        $sql = "INSERT INTO users (name, email) VALUES (?, ?)";
        $stmt = $pdo->prepare($sql);
        $stmt->execute([$name, $email]);
    } elseif (isset($_POST['update'])) {
        $id = $_POST['id'];
        $email = $_POST['email'];
        $sql = "UPDATE users SET email = ? WHERE id = ?";
        $stmt = $pdo->prepare($sql);
        $stmt->execute([$email, $id]);
    } elseif (isset($_POST['delete'])) {
        $id = $_POST['id'];
        $sql = "DELETE FROM users WHERE id = ?";
        $stmt = $pdo->prepare($sql);
        $stmt->execute([$id]);
    }
}

// 查询数据
$sql = "SELECT * FROM users";
$stmt = $pdo->query($sql);
$users = $stmt->fetchAll(PDO::FETCH_ASSOC);