使用php更改数据库中的数据

UPDATE users SET field_name = 'new_value' WHERE condition;

// 连接到数据库
$mysqli = new mysqli("localhost", "username", "password", "database");

// 检查连接是否成功
if ($mysqli->connect_errno) {
    die("连接数据库失败: " . $mysqli->connect_error);
}

// 准备SQL语句
$sql = "UPDATE users SET field_name = ? WHERE condition";

// 创建预处理语句
$stmt = $mysqli->prepare($sql);

// 绑定参数
$newValue = "new_value";
$stmt->bind_param("s", $newValue);

// 执行更新操作
$stmt->execute();

// 检查更新是否成功
if ($stmt->affected_rows > 0) {
    echo "数据更新成功";
} else {
    echo "数据更新失败";
}

// 关闭预处理语句和数据库连接
$stmt->close();
$mysqli->close();