mysqli实现增删改查

<?php
$host = 'localhost';
$user = 'username';
$password = 'password';
$dbname = 'database_name';

// 创建连接
$conn = new mysqli($host, $user, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
    die("连接失败: " . $conn->connect_error);
}

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

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

$stmt->execute();

echo "新记录插入成功";

$stmt->close();
$conn->close();
?>

<?php
// ... 连接数据库代码 ...

$sql = "DELETE FROM users WHERE id = ?";
$stmt = $conn->prepare($sql);
$stmt->bind_param("i", $id);

$id = 1;

$stmt->execute();

echo "记录删除成功";

$stmt->close();
$conn->close();
?>

<?php
// ... 连接数据库代码 ...

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

$email = "new.email@example.com";
$id = 1;

$stmt->execute();

echo "记录更新成功";

$stmt->close();
$conn->close();
?>

<?php
// ... 连接数据库代码 ...

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

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

$conn->close();
?>