Add an iterator method.

Author: lincanbin

src/PDO.class.php

@@ -11,41 +11,66 @@
  * 
  * A PHP MySQL PDO class similar to the the Python MySQLdb. 
  */
-require(dirname(__FILE__) . "/PDO.Log.class.php");
+require(__DIR__ . '/PDO.Log.class.php');
+require(__DIR__ . '/PDO.Iterator.class.php');
+/** Class DB
+ * @property PDO pdo PDO object
+ * @property PDOStatement sQuery PDOStatement
+ * @property PDOLog PDOLog logObject
+ */
 class DB
 {
 	private $Host;
+	private $DBPort;
 	private $DBName;
 	private $DBUser;
 	private $DBPassword;
-	private $DBPort;
 	private $pdo;
 	private $sQuery;
-	private $bConnected = false;
-	private $log;
+	private $connectionStatus = false;
+	private $logObject;
 	private $parameters;
 	public $rowCount   = 0;
 	public $columnCount   = 0;
 	public $querycount = 0;
-	
-	
-	public function __construct($Host, $DBName, $DBUser, $DBPassword, $DBPort = 3306)
+
+
+	private $retryAttempt = 0; // 失败重试次数
+	const AUTO_RECONNECT = true;
+	const RETRY_ATTEMPTS = 3; // 最大失败重试次数
+
+    /**
+     * DB constructor.
+     * @param $Host
+     * @param $DBPort
+     * @param $DBName
+     * @param $DBUser
+     * @param $DBPassword
+     */
+	public function __construct($Host, $DBPort, $DBName, $DBUser, $DBPassword)
 	{
-		$this->log        = new Log();
+		$this->logObject  = new PDOLog();
 		$this->Host       = $Host;
+		$this->DBPort     = $DBPort;
 		$this->DBName     = $DBName;
 		$this->DBUser     = $DBUser;
 		$this->DBPassword = $DBPassword;
-		$this->DBPort	  = $DBPort;
-		$this->Connect();
 		$this->parameters = array();
+		$this->Connect();
 	}
 
 
 	private function Connect()
 	{
 		try {
-			$this->pdo = new PDO('mysql:dbname=' . $this->DBName . ';host=' . $this->Host . ';port=' . $this->DBPort . ';charset=utf8', 
+			$dsn = 'mysql:';
+			$dsn .= 'host=' . $this->Host . ';';
+			$dsn .= 'port=' . $this->DBPort . ';';
+			if (!empty($this->DBName)) {
+				$dsn .= 'dbname=' . $this->DBName . ';';
+			}
+			$dsn .= 'charset=utf8;';
+			$this->pdo = new PDO($dsn,
 				$this->DBUser, 
 				$this->DBPassword,
 				array(
@@ -68,30 +93,36 @@ private function Connect()
 			//$this->pdo->setAttribute(PDO::ATTR_PERSISTENT, true);//长连接
 			$this->pdo->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true);
 			*/
-			$this->bConnected = true;
+			$this->connectionStatus = true;
 
 		}
 		catch (PDOException $e) {
-			echo $this->ExceptionLog($e->getMessage());
-			die();
+			$this->ExceptionLog($e, '', 'Connect');
 		}
 	}
-	
-	
-	public function CloseConnection()
+
+	private function SetFailureFlag()
 	{
 		$this->pdo = null;
+		$this->connectionStatus = false;
 	}
-	
-	
-	private function Init($query, $parameters = "")
+
+    /**
+     * close pdo connection
+     */
+	public function closeConnection()
+	{
+		$this->pdo = null;
+	}
+
+	private function Init($query, $parameters = null, $driverOptions = array())
 	{
-		if (!$this->bConnected) {
+		if (!$this->connectionStatus) {
 			$this->Connect();
 		}
 		try {
 			$this->parameters = $parameters;
-			$this->sQuery     = $this->pdo->prepare($this->BuildParams($query, $this->parameters));
+			$this->sQuery     = $this->pdo->prepare($this->BuildParams($query, $this->parameters), $driverOptions);
 
 			if (!empty($this->parameters)) {
 				if (array_key_exists(0, $parameters)) {
@@ -105,19 +136,22 @@ private function Init($query, $parameters = "")
 					$this->sQuery->bindParam($parametersType ? intval($column) : ":" . $column, $this->parameters[$column]); //It would be query after loop end(before 'sQuery->execute()').It is wrong to use $value.
 				}
 			}
-			
-			$this->succes = $this->sQuery->execute();
+
+			if (!isset($driverOptions[PDO::ATTR_CURSOR])) {
+                $this->sQuery->execute();
+            }
 			$this->querycount++;
 		}
 		catch (PDOException $e) {
-			echo $this->ExceptionLog($e->getMessage(), $this->BuildParams($query));
-			die();
+			$this->ExceptionLog($e, $this->BuildParams($query), 'Init', array('query' => $query, 'parameters' => $parameters));
+
 		}
 
 		$this->parameters = array();
 	}
 
-	private function BuildParams($query, $params = array()){
+	private function BuildParams($query, $params = null)
+	{
 		if (!empty($params)) {
 			$array_parameter_found = false;
 			foreach ($params as $parameter_key => $parameter) {
@@ -143,30 +177,116 @@ private function BuildParams($query, $params = array()){
 		}
 		return $query;
 	}
-	
-	
-	public function query($query, $params = null, $fetchmode = PDO::FETCH_ASSOC)
+
+    /**
+     * @return bool
+     */
+	public function beginTransaction()
+	{
+		return $this->pdo->beginTransaction();
+	}
+
+    /**
+     * @return bool
+     */
+	public function commit()
+	{
+		return $this->pdo->commit();
+	}
+
+    /**
+     * @return bool
+     */
+	public function rollBack()
+	{
+		return $this->pdo->rollBack();
+	}
+
+    /**
+     * @return bool
+     */
+	public function inTransaction()
+	{
+		return $this->pdo->inTransaction();
+	}
+
+    /**
+     * execute a sql query, returns an result array in the select operation, and returns the number of rows affected in other operations
+     * @param string $query
+     * @param null $params
+     * @param int $fetchMode
+     * @return array|int|null
+     */
+	public function query($query, $params = null, $fetchMode = PDO::FETCH_ASSOC)
 	{
 		$query        = trim($query);
 		$rawStatement = explode(" ", $query);
 		$this->Init($query, $params);
 		$statement = strtolower($rawStatement[0]);
 		if ($statement === 'select' || $statement === 'show') {
-			return $this->sQuery->fetchAll($fetchmode);
+			return $this->sQuery->fetchAll($fetchMode);
 		} elseif ($statement === 'insert' || $statement === 'update' || $statement === 'delete') {
 			return $this->sQuery->rowCount();
 		} else {
 			return NULL;
 		}
 	}
-	
-	
+
+    /**
+     * execute a sql query, returns an iterator in the select operation, and returns the number of rows affected in other operations
+     * @param string $query
+     * @param null $params
+     * @param int $fetchMode
+     * @return int|null|PDOIterator
+     */
+    public function iterator($query, $params = null, $fetchMode = PDO::FETCH_ASSOC)
+    {
+        $query        = trim($query);
+        $rawStatement = explode(" ", $query);
+        $this->Init($query, $params, array(PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL));
+        $statement = strtolower($rawStatement[0]);
+        if ($statement === 'select' || $statement === 'show') {
+            return new PDOIterator($this->sQuery, $fetchMode);
+        } elseif ($statement === 'insert' || $statement === 'update' || $statement === 'delete') {
+            return $this->sQuery->rowCount();
+        } else {
+            return NULL;
+        }
+    }
+
+    /**
+     * @param $tableName
+     * @param null $params
+     * @return bool|string
+     */
+	public function insert($tableName, $params = null)
+	{
+		$keys = array_keys($params);
+		$rowCount = $this->query(
+			'INSERT INTO `' . $tableName . '` (`' . implode('`,`', $keys) . '`) 
+			VALUES (:' . implode(',:', $keys) . ')',
+			$params
+		);
+		if ($rowCount === 0) {
+			return false;
+		}
+		return $this->lastInsertId();
+	}
+
+    /**
+     * @return string
+     */
 	public function lastInsertId()
 	{
 		return $this->pdo->lastInsertId();
 	}
-	
-	
+
+
+    /**
+     * @param $query
+     * @param null $params
+     * @return array
+     */
 	public function column($query, $params = null)
 	{
 		$this->Init($query, $params);
@@ -177,7 +297,12 @@ public function column($query, $params = null)
 		return $resultColumn;
 	}
 
-
+    /**
+     * @param $query
+     * @param null $params
+     * @param int $fetchmode
+     * @return mixed
+     */
 	public function row($query, $params = null, $fetchmode = PDO::FETCH_ASSOC)
 	{
 		$this->Init($query, $params);
@@ -187,28 +312,56 @@ public function row($query, $params = null, $fetchmode = PDO::FETCH_ASSOC)
 		$this->sQuery->closeCursor();
 		return $resultRow;
 	}
-	
-	
+
+    /**
+     * @param $query
+     * @param null $params
+     * @return mixed
+     */
 	public function single($query, $params = null)
 	{
 		$this->Init($query, $params);
 		return $this->sQuery->fetchColumn();
 	}
-	
-	
-	private function ExceptionLog($message, $sql = "")
+
+    /**
+     * @param PDOException $e
+     * @param string $sql
+     * @param string $method
+     * @param array $parameters
+     */
+	private function ExceptionLog(PDOException $e, $sql = "", $method = '', $parameters = array())
 	{
+		$message = $e->getMessage();
 		$exception = 'Unhandled Exception. <br />';
 		$exception .= $message;
 		$exception .= "<br /> You can find the error back in the log.";
 
 		if (!empty($sql)) {
 			$message .= "\r\nRaw SQL : " . $sql;
 		}
-		$this->log->write($message, $this->DBName . md5($this->DBPassword));
-		//Prevent search engines to crawl
-		header("HTTP/1.1 500 Internal Server Error");
-		header("Status: 500 Internal Server Error");
-		return $exception;
+		$this->logObject->write($message, $this->DBName . md5($this->DBPassword));
+		if (
+			self::AUTO_RECONNECT
+			&& $this->retryAttempt < self::RETRY_ATTEMPTS
+			&& stripos($message, 'server has gone away') !== false
+			&& !empty($method)
+			&& !$this->inTransaction()
+		) {
+			$this->SetFailureFlag();
+			$this->retryAttempt ++;
+			$this->logObject->write('Retry ' . $this->retryAttempt . ' times', $this->DBName . md5($this->DBPassword));
+			call_user_func_array(array($this, $method), $parameters);
+		} else {
+			if (($this->pdo === null || !$this->inTransaction()) && php_sapi_name() !== "cli") {
+				//Prevent search engines to crawl
+				header("HTTP/1.1 500 Internal Server Error");
+				header("Status: 500 Internal Server Error");
+				echo $exception;
+				exit();
+			} else {
+				throw $e;
+			}
+		}
 	}
 }