MySQL错误码 2013 分析与解决方案

'pdo_code' => 'HY000',
'db_code' => 2013,
'db_error' => 'Lost connection to MySQL server during query'

// 数据库连接配置
$dbConfig = [
  'host' => 'localhost',
  'dbname' => 'your_database',
  'username' => 'root',
  'password' => 'password',
  'charset' => 'utf8mb4'
];

// 创建数据库连接（带重连机制）
function createConnection($config) {
  $maxRetries = 3;
  $retryCount = 0;

  while ($retryCount < $maxRetries) {
    try {
      $dsn = "mysql:host={$config['host']};dbname={$config['dbname']};charset={$config['charset']}";
      $pdo = new PDO($dsn, $config['username'], $config['password']);
      $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
      return $pdo;
    } catch (PDOException $e) {
      $retryCount++;
      // 等待后重试
      sleep(1);
    }
  }
  throw new Exception("无法连接到数据库服务器");
}

// 执行查询（带连接检查）
function executeQuery($pdo, $sql, $params = []) {
  try {
    $stmt = $pdo->prepare($sql);
    $stmt->execute($params);
    return $stmt;
  } catch (PDOException $e) {
    // 检查是否为连接丢失错误
    if ($e->getCode() == 'HY000' &&
        strpos($e->getMessage(), 'Lost connection') !== false) {
      // 重新建立连接并重试
      $pdo = createConnection($GLOBALS['dbConfig']);
      $stmt = $pdo->prepare($sql);
      $stmt->execute($params);
      return $stmt;
    } else {
      throw $e;
    }
  }
}

# 查看当前连接状态
SHOW PROCESSLIST;

# 查看连接超时设置
SHOW VARIABLES LIKE '%timeout%';

# 查看最大数据包大小
SHOW VARIABLES LIKE 'max_allowed_packet';

# 查看连接数统计
SHOW STATUS LIKE 'Threads_connected';
SHOW STATUS LIKE 'Threads_running';