更新数据

使用 MySQLi 和 PDO 更新 MySQL 表中的数据

UPDATE 语句用于更新表中的现有记录：

UPDATE table_name
SET column1=value, column2=value2,...
WHERE some_column=some_value 

注意：UPDATE 语法中的 WHERE 子句：WHERE 子句指定应更新哪条或哪些记录。若省略 WHERE 子句，所有记录都将更新！

请参阅：SQL 教程。

让我们看看 "MyGuests" 表：

id	firstname	lastname	email	reg_date
1	John	Doe	john@example.com	2014-10-22 14:26:15
2	Mary	Moe	mary@example.com	2014-10-23 10:22:30

以下示例更新了 "MyGuests" 表中 id=2 的记录：

实例（MySQLi 面向对象）

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

// 创建连接
$conn = new mysqli($servername, $username, $password, $dbname);
// 检查连接
if ($conn->connect_error) {
  die("连接失败：" . $conn->connect_error);
}

$sql = "UPDATE MyGuests SET lastname='Doe' WHERE id=2";

if ($conn->query($sql) === TRUE) {
  echo "记录更新成功";
} else {
  echo "更新记录时出错：" . $conn->error;
}

$conn->close();
?>

实例（MySQLi 过程化）

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

// 创建连接
$conn = mysqli_connect($servername, $username, $password, $dbname);
// 检查连接
if (!$conn) {
  die("连接失败：" . mysqli_connect_error());
}

$sql = "UPDATE MyGuests SET lastname='Doe' WHERE id=2";

if (mysqli_query($conn, $sql)) {
  echo "记录更新成功";
} else {
  echo "更新记录时出错：" . mysqli_error($conn);
}

mysqli_close($conn);
?>

实例（PDO）

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

try {
  $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
  // 将 PDO 错误模式设置为异常
  $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

  $sql = "UPDATE MyGuests SET lastname='Doe' WHERE id=2";

  // 准备语句
  $stmt = $conn->prepare($sql);

  // 执行查询
  $stmt->execute();

  // 输出一条消息，表示 UPDATE 成功
  echo $stmt->rowCount() . " 条记录已成功更新";
} catch(PDOException $e) {
  echo $sql . "<br>" . $e->getMessage();
}

$conn = null;
?>

记录更新后，表将如下所示：

id	firstname	lastname	email	reg_date
1	John	Doe	john@example.com	2014-10-22 14:26:15
2	Mary	Doe	mary@example.com	2014-10-23 10:22:30