封装的 PDO 操作数据库 的帮助类 MySqlHelper 

封装的 PDO 操作数据库 的帮助类 MySqlHelper ,仅供学习交流使用！

<?php
/**
 * Description of MySqlHelper
 *
 * @author fx678
 */
 class MySqlHelper {
    private static $pdoDB = null;
    
    public function __destruct() {
        $this->pdoDB = null;
    }
    
    
    /**
     * 获取ini配置文件中PDO连接信息，并返回PDO对象
     * $section: 数据库配置节点
     * 返回 PDO对象
     **/
    private static function getPdoDB($section ="db"){
        if(self::$pdoDB !== null && !array_key_exists($section,array('dsn','username','password'))){
            if(!array_key_exists($section,self::$pdoDB)){
                return self::$pdoDB;
            }
        }   
        
        $config = Config::getConfig($section);
        try {
            self::$pdoDB = new PDO(
                    $config['dsn'], 
                    $config['username'], 
                    $config['password'], 
                    array(PDO::MYSQL_ATTR_INIT_COMMAND => "SET NAMES 'utf8';")
            );    
        } catch (Exception $ex) {
            throw new Exception('DB connection error:'.$ex->getMessage());
        }
        
        return self::$pdoDB;
    }
    
    
    /**
     * 执行不带参数的查询语句
     * $connectionString:数据库配置信息节点
     * $strSql：要执行的T-sql 语句
     * 返回 PDOStatement 对象
     **/
    public static function query($connectionString,$strSql){
        try {
           $statement = self::getPdoDB($connectionString)->query($strSql,PDO::FETCH_ASSOC);
           
           if($statement === false){
               throw new Exception($this->getDB($connectionString)->errorInfo());
           }
        } catch (Exception $ex) {
            throw new Execption($ex->getMessage());
        }
        
        return $statement;
     }

     
   /**
     * 执行带参数的查询语句
     * $connectionString:数据库配置信息节点
     * $strSql：要执行的T-sql 语句
     * $paramArr：参数数组
     * 返回 PDOStatement 对象
     **/
    public static function queryParam($connectionString,$strSql,$paramArr){
        try {
            $statement = self::getPdoDB($connectionString)->prepare($strSql);
            
            //获取对应参数
            if(isset($paramArr) && is_array($paramArr)){
                foreach ($paramArr as $key => $val) {
                    $statement->bindParam("$key",$val[0],$val[1]);
                }
            }
            
            //执行
            $statement->execute();    
        } catch (Exception $ex) {
            throw new Execption($ex->getMessage());
        }
        
        if($statement === false){
            throw new Exception($this->getDB($connectionString)->errorInfo());
        }
        
        return $statement;
    }
    
    
    /**
     * 执行带参数并使用事物机制的(增删改)语句
     * $connectionString:数据库配置信息节点
     * $strSql：要执行的T-sql 语句
     * $paramArr：参数数组
     * 返回 返回受影响的行数(int)
     **/
    public static function prepareParamTransaction($connectionString,$strSql,$paramArr){
        $count = 0;
        
        try {
            $pdo = self::getPdoDB($connectionString);
            //关闭自动提交(默认为自动提交)
            $pdo ->setAttribute(PDO::ATTR_AUTOCOMMIT, 0);
            //开启异常处理
            $pdo -> setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); 
            
            //开始事物
            $pdo -> beginTransaction();
            
            //获取 Statement 对象
            $statement = $pdo->prepare($strSql);
                            
           //获取对应参数
            if(isset($paramArr) && is_array($paramArr)){
                  foreach ($paramArr as $key => $val) {
                      $statement->bindParam("$key",$val[0],$val[1]);
                  }
            }
            
            //执行
            $statement -> execute();
            $count = (int)($statement-> rowCount());
            
            //提交事物
            $pdo -> commit();
        } catch (Exception $ex){
            throw new Execption($ex->getMessage());
        }
        
        if($statement === false){
            throw new Exception($this->getPdoDB($connectionString)->errorInfo());
        }
        
        //返回受影响的行数
        return $count;
    }
}

?>

调用参考示例1：

 $strSql = "SELECT * FROM NEWSINDEX n WHERE n.`Id`=:Id LIMIT 1;";
        
        $paramArr = array(
            ':Id' => array($Id,  PDO::PARAM_INT)
        );
        
        foreach (self::queryParam(self::$connectionString, $strSql, $paramArr) as $row) {
            $model = new htNewsIndex();
            HtNewsIndexMapper::map($model, $row);
            return $model;
        }
        
        return null;

调用参考示例2：

$strSql = "INSERT INTO NEWS_INDEX(BSID,IDX_PERIOD,PREVIOUS_PRICE,ACTUAL_PRICE,REVISED_PRICE,SURVEY_PRICE,PUBLISH_TIME,CREATE_TIME,STATUS) "
        . "VALUES(:BSId,:IdxPeriod,:PreviousPrice,:ActualPrice,:RevisedPrice,:SurveyPrice,:PublishTime,:CreateTime,:Status);";
        
        //参数数组
        $params = array(
            ':BSId'           => array($model->getBSId(),PDO::PARAM_STR),
            ':IdxPeriod'      => array($model->getIdxPeriod(),PDO::PARAM_STR),
            ':PreviousPrice'  => array($model->getPreviousPrice(),PDO::PARAM_STR),
            ':ActualPrice'    => array($model->getActualPrice(),PDO::PARAM_STR),
            ':RevisedPrice'   => array($model->getRevisedPrice(),PDO::PARAM_STR),
            ':SurveyPrice'    => array($model->getSurveyPrice(),PDO::PARAM_STR),
            ':PublishTime'    => array($model->getPublishTime(),PDO::PARAM_STR),
            ':CreateTime'     => array($model->getCreateTime(),PDO::PARAM_STR),
            ':Status'         => array($model->getStatus(),PDO::PARAM_INT)
        );
        
        try {
           return (int)self::prepareParamTransaction(self::$connectionString,$strSql,$params);
        } catch (Exception $ex) {
            throw new Exception($ex->getTraceAsString());
        }

由于认识有限，不足之处请多指教！
在这个过程中，我发现使用 PDO 参数化模糊查询，始终没有结果，也没有异常抛出，如下语句：

SELECT * FROM NEWS n WHERE n.`Title` LIKE('%:key%');

SELECT * FROM NEWS n WHERE n.`Title` LIKE('%?%');

封装的 PDO 操作数据库 的帮助类 MySqlHelper