数据库PDO操作基类

<?php
/*
* PHP-PDO-MySQL-Class
* https://github.com/lincanbin/PHP-PDO-MySQL-Class
*
* Copyright 2015 Canbin Lin ([email protected])
* http://www.94cb.com/
*
* Licensed under the Apache License, Version 2.0:
* http://www.apache.org/licenses/LICENSE-2.0
*
* A PHP MySQL PDO class similar to the the Python MySQLdb.
*/

class PDODB
{
    private $Host;
    private $DBName;
    private $DBUser;
    private $DBPassword;
    private $pdo;
    private $sQuery;
    private $bConnected = false;
    private $log;
    private $parameters;
    public $rowCount   = 0;
    public $columnCount   = 0;
    public $querycount = 0;


    public function __construct($Host, $DBName, $DBUser, $DBPassword)
    {
        $db_config      = require_once(ROOT_PATH .'/src/mysqlconfig.php');

        $this->log        = new DBLog();
        $this->Host       = $db_config["DB_CONFIG"]["DB_HOST"];
        $this->DBName     = $db_config["DB_CONFIG"]["DB_NAME"];
        $this->DBUser     = $db_config["DB_CONFIG"]["DB_USER"];;
        $this->DBPassword = $db_config["DB_CONFIG"]["DB_PWD"];;
        $this->Connect();
        $this->parameters = array();
    }


    private function Connect()
    {
        try {
            $this->pdo = new PDO('mysql:dbname=' . $this->DBName . ';host=' . $this->Host . ';charset=utf8',
                $this->DBUser,
                $this->DBPassword,
                array(
                    //For PHP 5.3.6 or lower
                    PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES utf8",
                    PDO::ATTR_EMULATE_PREPARES => false,

                    //长连接
                    //PDO::ATTR_PERSISTENT => true,

                    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
                    PDO::MYSQL_ATTR_USE_BUFFERED_QUERY => true
                )
            );
            /*
            //For PHP 5.3.6 or lower
            $this->pdo->setAttribute(PDO::MYSQL_ATTR_INIT_COMMAND, 'SET NAMES utf8');
            $this->pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
            $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
            //$this->pdo->setAttribute(PDO::ATTR_PERSISTENT, true);//长连接
            $this->pdo->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, true);
            */
            $this->bConnected = true;

        }
        catch (PDOException $e) {
            echo $this->ExceptionLog($e->getMessage());
            die();
        }
    }


    public function CloseConnection()
    {
        $this->pdo = null;
    }


    private function Init($query, $parameters = "")
    {
        if (!$this->bConnected) {
            $this->Connect();
        }
        try {
            $this->parameters = $parameters;
            $this->sQuery     = $this->pdo->prepare($this->BuildParams($query, $this->parameters));

            if (!empty($this->parameters)) {
                if (array_key_exists(0, $parameters)) {
                    $parametersType = true;
                    array_unshift($this->parameters, "");
                    unset($this->parameters[0]);
                } else {
                    $parametersType = false;
                }
                foreach ($this->parameters as $column => $value) {
                    $this->sQuery->bindParam($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();
            $this->querycount++;
        }
        catch (PDOException $e) {
            echo $this->ExceptionLog($e->getMessage(), $this->BuildParams($query));
            die();
        }

        $this->parameters = array();
    }

    private function BuildParams($query, $params = null)
    {
        if (!empty($params)) {
            $rawStatement = explode(" ", $query);
            foreach ($rawStatement as $value) {
                if (strtolower($value) == 'in') {
                    return str_replace("(?)", "(" . implode(",", array_fill(0, count($params), "?")) . ")", $query);
                }
            }
        }
        return $query;
    }


    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);
        } elseif ($statement === 'insert' || $statement === 'update' || $statement === 'delete') {
            return $this->sQuery->rowCount();
        } else {
            return NULL;
        }
    }


    public function lastInsertId()
    {
        return $this->pdo->lastInsertId();
    }


    public function column($query, $params = null)
    {
        $this->Init($query, $params);
        $resultColumn = $this->sQuery->fetchAll(PDO::FETCH_COLUMN);
        $this->rowCount = $this->sQuery->rowCount();
        $this->columnCount = $this->sQuery->columnCount();
        $this->sQuery->closeCursor();
        return $resultColumn;
    }


    public function row($query, $params = null, $fetchmode = PDO::FETCH_ASSOC)
    {
        $this->Init($query, $params);
        $resultRow = $this->sQuery->fetch($fetchmode);
        $this->rowCount = $this->sQuery->rowCount();
        $this->columnCount = $this->sQuery->columnCount();
        $this->sQuery->closeCursor();
        return $resultRow;
    }


    public function single($query, $params = null)
    {
        $this->Init($query, $params);
        return $this->sQuery->fetchColumn();
    }


    private function ExceptionLog($message, $sql = "")
    {
        $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;
    }
}