自定义PDO封装类

<?php
class Db
{
    protected static $_instance = null; // 定义标识符(通过$_instance值得改变情况，来判定Model类是否被实例化)
    protected  $dbName = '';
    protected  $dsn = '';
    protected  $pdo = '';

    protected $prefix='wy_';
    protected $_table;
    protected $isShowSql=false;
    protected $tablesName=null;
    protected $al=[];//计算数组维度的临时数组
    protected $where=[];//where数组
    protected $sqlWhereParten;//wheresql片段
    protected $whereOr=[];//whereOr数组
    protected $sqlWhereOrParten;//whereOrsql片段
    protected $selectField='*';//查询字段
    protected $limit='';
    protected $order='asc';
    protected $group;
    protected $having;
 
      /**
       * 析构方法
       * final方法不能被继承
       * 由于instance静态方法的原因__construct()只执行一次 
       * 第一次得到的对象后，在后面的访问直接返回该对象
       * @param string $dbHost    服务器地址
       * @param string $dbUser    数据库用户名
       * @param string $dbPasswd  数据库密码
       * @param string $dbName    操作的数据库名
       * @param string $dbCharset 数据库字符集
       */
    private final function __construct($dbHost, $dbUser, $dbPasswd, $dbName, $dbCharset){ 

        try {
            $this->dbName=$dbName;
            $this->dsn = 'mysql:host='.$dbHost.';dbname='.$dbName;
            $this->pdo = new PDO($this->dsn, $dbUser, $dbPasswd);
            $this->pdo->query("set names utf8"); //数据库utf8
            $this->pdo->exec('SET character_set_connection='.$dbCharset.', character_set_results='.$dbCharset.', character_set_client=binary');
        } catch (PDOException $e) {
            $this->outputError($e->getMessage());
        }

    }

     /**
     * 防止克隆
     * 
     */
    private function __clone() {}


    /**
     * 申明静态方法，由类名直接调用此方法，来实例化Model类
     * 在静态方法中，绝不可以使用$this($this是对象产生之后才会有的)
       * @param string $dbHost    服务器地址
       * @param string $dbUser    数据库用户名
       * @param string $dbPasswd  数据库密码
       * @param string $dbName    操作的数据库名
       * @param string $dbCharset 数据库字符集
     * @return object           返回当前Db对象
     */
    public static function instance($dbHost, $dbUser, $dbPasswd, $dbName, $dbCharset)
    {
        // 实例化Model类
        if (self::$_instance == null) {
        // self:代表自身(self=Model)
        self::$_instance = new self($dbHost, $dbUser, $dbPasswd, $dbName, $dbCharset);
        }

        return self::$_instance;
    }

    /**
     * destruct 关闭数据库连接
     */
    public function destruct()
    {
        $this->dbh = null;
    }   




    /**
     * 查询
     * @param  [type] $sql [description]
     * @return [type]      [description]
     */
    public function query($sql,$queryMode='All')
    {    
        $queryMode=strtolower($queryMode);
        $recordset = $this->pdo->query($sql);
        $this->getPDOError();
        if ($recordset) {
            $recordset->setFetchMode(PDO::FETCH_ASSOC);
            if ($queryMode == 'all') {
                $result = $recordset->fetchAll();
            } elseif ($queryMode == 'row') {
                $result = $recordset->fetch();
            }
        } else {
            $result = null;
        }
        return $result;
    }
    /**
     * 增改
     * @param  [type] $sql [description]
     * @return [type]      [description]
     */
    public function exec($sql)
    {
        $resRow=$this->pdo->exec($sql);
        return $resRow;
    }

    /**
     * 执行预处理sql
     *
     * $sql="update good SET goods_store=goods_store-:num WHERE id=:id";
     * $pdo->executeSql($sql,['num'=>1,'id'=>1]);
     * @param  [type] $sql [description]
     * @param  [type] $map [description]
     * @return [type]      [description]
     */
    public function executeSql($sql,$map=[])
    {
        $stmt=$this->pdo->prepare($sql);
        /*                
            $stmt->bindvalue(':num',1000);
            $stmt->bindvalue(':id',2);
            or
            $stmt->bindParam(':num', $num,PDO::PARAM_INT);
            $stmt->bindParam(':id', $id,PDO::PARAM_INT);

            $res2=$stmt->execute();//成功返回行数

            $res2=$stmt->execute();
        */
        $res=$stmt->execute($map);//成功返回行数
        $this->getPDOError();
        return $res;
    }

    public function insert($map=[])
    {    
        if(empty($table=$this->_table)){
            throw new Exception("Param Error: 缺少表名,执行插入操作前请调用table('tablename')获取");    
        }
        
        $dataPartten='';
        foreach ($map as $key => $value) {
            $dataPartten.=$key.'=:'.$key.',';
        }
        
        $dataPartten=rtrim($dataPartten,',');

        $sql="INSERT INTO ".$this->prefix.$table.' SET '.$dataPartten;
        if($this->isShowSql){
            $this->isShowSql=false;
            return $sql;
        }
        //INSERT INTO users (name, age) VALUES('姚明',25);
        //INSERT INTO uses SET name = '姚明', age = 25;
        $stmt=$this->pdo->prepare($sql);
        $res=$stmt->execute($map);//成功返回行数
        $this->getPDOError();
        return $res;
    }

    public function update($data=[])
    {
        /*
         * $sql="update good SET goods_store=goods_store-:num WHERE id=:id";
         * $pdo->executeSql($sql,['num'=>1,'id'=>1]);
         */
        if($this->arrLevel($data)>1){
            $this->outputError('数组格式不正确');
        }
        $sqlData='';
        foreach ($data as $field => $value) {
            $sqlData.=$field.'='.':'.$field.',';
        }
        $sqlData=rtrim($sqlData,',');

        


        //$sql="update o2o_user SET mobile='15632613871',update_time={$time} WHERE id=11";
        

        $sql="UPDATE ".$this->prefix.$this->_table.' SET '.$sqlData;
            
        

        if(!empty($this->where)){
            
            $sql.=' WHERE '.$this->sqlWhereParten;
        }
        
        if(!empty($this->whereOr)){
            $sql.=' OR '.$this->sqlWhereOrParten;
        }

        if($this->isShowSql){
            $this->isShowSql=false;
            return $sql;
        }
        $stmt=$this->pdo->prepare($sql);
        $map=array_merge($this->where,$this->whereOr,$data);

        $res=$stmt->execute($map);//成功返回行数
        $this->getPDOError();

        return $res;

    }


    public function find($id='')
    {

        if(empty($this->_table)){
            $this->outputError('表名为空请用table方法获取');
        }
        if(!empty($this->sqlWhereOrParten)){
            $whereor=" OR ".$this->sqlWhereOrParten;
        }else{
            $whereor='';
        }
        $sql="select ".$this->selectField." FROM ".$this->prefix.$this->_table." WHERE ".$this->sqlWhereParten." ".$whereor." ".$this->group." ".$this->having." ".$this->order." ".$this->limit;
        
        if($this->isShowSql){
            $this->isShowSql=false;
            return $sql;
        }
        $stmt=$this->pdo->prepare($sql);
        $map=array_merge($this->where,$this->whereOr);

        $stmt->execute($map);//成功返回true
        $this->getPDOError();
        //查询多条数据
        $result=$stmt->fetch(PDO::FETCH_ASSOC);//关联数组

        return $result;


    }

    public function select($id='')
    {
        if(empty($this->_table)){
            $this->outputError('表名为空请用table方法获取');
        }

        if(!empty($this->sqlWhereOrParten)){
            $whereor=" OR ".$this->sqlWhereOrParten;
        }else{
            $whereor='';
        }

        $sql="select ".$this->selectField." FROM ".$this->prefix.$this->_table." WHERE ".$this->sqlWhereParten." ".$whereor." ".$this->group." ".$this->having." ".$this->order." ".$this->limit;
        if($this->isShowSql){
            $this->isShowSql=false;
            return $sql;
        }
        $stmt=$this->pdo->prepare($sql);
        $map=array_merge($this->where,$this->whereOr);

        $stmt->execute($map);//成功返回true
        $this->getPDOError();
        //查询多条数据
        $result=$stmt->fetchAll(PDO::FETCH_ASSOC);//关联数组

        return $result;            
    }


    public function delete()
    {
        //$sql = "delete from stu where id=?";
        if(empty($this->_table)){
            $this->outputError('表名为空请用table方法获取');
        }

        $sql="DELETE FROM ".$this->prefix.$this->_table;
        if(!empty($this->where)){
            
            $sql.=' WHERE '.$this->sqlWhereParten;
        }
        
        if(!empty($this->whereOr)&&!empty($this->where)){
            $sql.=' OR '.$this->sqlWhereOrParten;
        }

        if($this->isShowSql){
            $this->isShowSql=false;
            return $sql;
        }

        $stmt = $this->pdo->prepare($sql);//准备sql模板
        $map=array_merge($this->where,$this->whereOr);
        $stmt->execute($map);//执行预处理语句
        $this->getPDOError();
        $affect_row = $stmt->rowCount();

        return $affect_row;

    }

    public function setInc($field,$num=1)
    {    
        
        $field=strval($field);
        $num=intval($num);
        if(empty($this->_table)){
            $this->outputError('表名为空请用table方法获取');
        }


        $sql="UPDATE ".$this->prefix.$this->_table." SET ".$field."=".$field."+:num ";
        

        if(!empty($this->where)){
            
            $sql.=' WHERE '.$this->sqlWhereParten;
        }
        
        if(!empty($this->whereOr)&&!empty($this->where)){
            $sql.=' OR '.$this->sqlWhereOrParten;
        }


        if($this->isShowSql){
            $this->isShowSql=false;
            return $sql;
        }

        $stmt = $this->pdo->prepare($sql);//准备sql模板
        $map=array_merge($this->where,$this->whereOr);
        $map['num']=$num;    

        $stmt->execute($map);//执行预处理语句
        $this->getPDOError();
        $affect_row = $stmt->rowCount();
        return $affect_row;
    }

    /**
     * 递减
     * @param [type] $field [description]
     * @param [type] $num   [description]
     */
    public function setDec($field,$num)
    {
        $field=strval($field);
        $num=intval($num);
        if(empty($this->_table)){
            $this->outputError('表名为空请用table方法获取');
        }


        $sql="UPDATE ".$this->prefix.$this->_table." SET ".$field."=".$field."-:num ";
        

        if(!empty($this->where)){
            
            $sql.=' WHERE '.$this->sqlWhereParten;
        }
        
        if(!empty($this->whereOr)&&!empty($this->where)){
            $sql.=' OR '.$this->sqlWhereOrParten;
        }


        if($this->isShowSql){
            $this->isShowSql=false;
            return $sql;
        }

        $stmt = $this->pdo->prepare($sql);//准备sql模板
        $map=array_merge($this->where,$this->whereOr);
        $map['num']=$num;    

        $stmt->execute($map);//执行预处理语句
        $this->getPDOError();
        $affect_row = $stmt->rowCount();
        return $affect_row;        
    }





    public function field($field='*')
    {
        $this->selectField=trim($field);
        return $this;
    }

    public function limit($a,$b=''){
        //limit 10          等于 limit 0 10  查前10条
        //limit 10 1000      查询10条以后的 1000条数据 即 11-10010

        $a=abs(intval($a));
        if(!empty($b)){
            $b=abs(intval($b));
        }
    
        $sql= 'limit '.$a.','.$b;
        $sql=rtrim($sql,',');
        $this->limit=$sql;
        return $this;
    }

    /*
        order('id,name[asc]');
     */
    public function order($order='asc')
    {    //默认 orderby id asc
        //order by name,id desc
        
        $order=trim(strval($order));
        $order=strtr($order,' ',',');//将' '替换成，

        $arr=array_filter(explode(',',$order));

        $temp='';
        foreach ($arr as $key => $field) {
            $pos=stripos($field,'[');
            if($pos!==false){
                if($pos===0){
                    unset($arr[$key]);
                }else{
                    $arrValue=substr($field,0,$pos);
                    $arr[$key]=$arrValue;
                }
                
                $ade=trim(substr($field,$pos),'[]');
                //当ade为默认的asc不取值去掉它
                if($ade=='desc'){
                    $temp=$ade;
                }
            }
        }
        $order=implode($arr,',');

        if(!empty($order)){
            $sql="ORDER BY ".$order.' '.strtoupper($temp);
            $sql=trim($sql);
        }else{
            $sql='';
        }    

        $this->order=$sql;
        return $this;
    }

    public function group($field='')
    {
        return $this;
    }

    public function having(){
        return $this;
    }




    /**
     * where (id=1 and name=1 ) or (id=2 and ) 
     * @param  [type] $where [description]
     * @return [type]        [description]
     */
    public function where($where)
    {
        /*
            where id in(1,3,5)
            where id>5 and id<10
            where id between 40 and 50;

         */

        if($this->arrLevel($where)>2){
            $this->outputError('数组格式不正确');
        }
        $sql='';
        $wh=[];
        foreach ($where as $field => $values){
            
            if(is_array($values)){
                if($values['0']=='range'){
                    $arr=explode(',', $values[1],2);
                    $newarr=[];

                    $sql.=$field.' >:wh_'.$field.'Min AND '.$field.' <:wh_'.$field.'Max AND ';
                    $wh[$field.'Min']=min($arr);    
                    $wh[$field.'Max']=max($arr);    
                }else{
                    $sql.=$field.' '.$values[0].':wh_'.$field.' AND '; 
                    $wh['wh_'.$field]=$values[1];
                }

            }elseif (is_string($values)||is_int($values)) {
                $sql.=$field.'='.':wh_'.$field.' AND ';
                $wh['wh_'.$field]=$values; 
            }else{
                $this->outputError('数组格式不正确');
            }    
        }

        $sql='('.substr($sql,0,-5).')';

        $this->sqlWhereParten=null;
        $this->sqlWhereParten=$sql;
        $this->where=[];
        $this->where=$wh;


        return $this;
    }

    /**
     * where (id=1 and name=1 ) or (id=2 and ) 
     * @param  [type] $where [description]
     * @return [type]        [description]
     */
    public function whereOr($whereOr)
    {

        if($this->arrLevel($whereOr)>2){
            $this->outputError('数组格式不正确');
        }
        $sql='';
        $wh=[];
        foreach ($whereOr as $field => $values){
            
            if(is_array($values)){

                if($values['0']=='range'){
                    $arr=explode(',', $values[1],2);
                    $newarr=[];

                    $sql.=$field.' >:whor_'.$field.'Min AND '.$field.' <:whor_'.$field.'Max AND ';
                    $wh['whor_'.$field.'Min']=min($arr);    
                    $wh['whor_'.$field.'Max']=max($arr);    
                }else{
                    $sql.=$field.' '.$values[0].':whor_'.$field.' AND '; 
                    $wh['whor_'.$field]=$values[1];
                }
                
            }elseif (is_string($values)||is_int($values)) {
                $sql.=$field.'='.':whor_'.$field.' AND ';
                $wh['whor_'.$field]=$values; 
            }else{
                $this->outputError('数组格式不正确');
            }    
        }

        $sql='('.substr($sql,0,-5).')';
        $this->sqlWhereOrParten=null;
        $this->sqlWhereOrParten=trim($sql);
        $this->whereOr=[];
        $this->whereOr=$wh;

        return $this;
    }





    

    public function showSql($flag=false)
    {
        $this->isShowSql=$flag;
        return $this;
    }

    public function table($tablename='')
    {    
        $this->tableExists($tablename);
        if(!empty($tablename)){
            $this->_table=$tablename;
        }
        return $this;
    }


    /**
     * 预处理
     * @param  string $sql [description]
     * @return [type]      [description]
     */
    public function prepare($sql=''){
        return $this->pdo->prepare($sql);
    }

    /**
     * 执行预处理语句
     * @param  [type] $presql [description]
     * @return [type]         [description]
     */
    public function execute($presql){
        return $this->pdo->execute($presql);
    }


    /**
     * checkFields 检查指定字段是否在指定数据表中存在
     *
     * @param String $table
     * @param array $arrayField
     */
    private function checkFields($table, $arrayFields)
    {
        //没必要加上$this->tableExists($table); getField有啦
        $fields = $this->getFields($table);
        foreach ($arrayFields as $key => $value) {
            if (!in_array($key, $fields)) {
                $this->outputError("Unknown column `$key` in field list.");
            }
        }
    }

    /**
     * getFields 获取指定数据表中的全部字段名
     *
     * @param String $table 表名
     * @return array
     */
    private function getFields($table)
    {
        $this->tableExists($table);
        $fields = array();
        $sql= "SHOW COLUMNS FROM ".$this->prefix.$table;
        $recordset = $this->pdo->query($sql);
        $this->getPDOError();
        $recordset->setFetchMode(PDO::FETCH_ASSOC);
        $result = $recordset->fetchAll();
        foreach ($result as $rows) {    
            $fields[] = $rows['Field'];
        }
        return $fields;
    }

    /**
     * 获取当前连接库的所有表名
     * @param  string $dbname [description]
     * @return [type]         [description]
     */
    public function getTableNames($dbname='')
    {        
        if($this->tablesName!==null&&is_array($this->tablesName)){
            return $this->tablesName;
        }
        $dbname=$this->dbName;
        $sql="select table_name from information_schema.tables where table_schema='$dbname'";
        $data=$this->query($sql);
        $this->getPDOError();
        $prefix=$this->prefix;
        $prefixLength=strlen($prefix);    
        
        

        $tables=[];
        foreach ($data as $key => $val) {
            if(!empty($prefix)){                
                $tables[]=substr($val['table_name'],$prefixLength);
            }else{
                $tables[]=$val['table_name'];
            }
        }
        $this->tablesName=$tables;

        return $tables;
    }

    /**
     * 检测当前连接数据库是否存在该表名
     * @param  string $tablename 查询的表名
     * @return boolean or Exception           返回true或者抛出异常
     */
    public function tableExists($tablename)
    {
        if(in_array($tablename,$this->getTableNames())){
            return true;
        }

        $this->outputError("当前数据库没有此表[{$this->prefix}$tablename],请核对表名是否正确");
    }


    /**
     * 检查是否在一个事务内
     * 
     * @return [type] [description]
     */
    public function inTransaction()
    {    
        if($this->pdo->inTransaction()){
            return true;    
        }else{
            return false;
        }
    }

    /**
     * 获取表引擎
     * 
     * @param String $tableName 表名
     * @param String $dbName 库名
     * @param Boolean $debug
     * @return String
     */
    public function getTableEngine($tableName,$dbName='')
    {
        if(empty($dbName)){
            $dbName=$this->dbName;
        }
        $this->tableExists($tableName);

        $strSql = "SHOW TABLE STATUS FROM $dbName WHERE Name='".$this->prefix.$tableName."'";
        $arrayTableInfo = $this->query($strSql,'all');
        $this->getPDOError();
        return $arrayTableInfo[0]['Engine'];
    }
    /**
     * 获取mysql支持的引擎
     * @return [type] [description]
     */
    public function getEngines()
    {
        $sql="show Engines";
        $resInfo=$this->query($sql);
        $this->getPDOError();
        return $resInfo;

    }
    /**
     * 获取建表默认引擎
     * @return [type] [description]
     */
    public function getDefaultEngines()
    {
        $sql="show variables like 'default_storage_engine'";
        $resInfo=$this->query($sql);
        $this->getPDOError();
        return $resInfo[0]['Value'];
    } 

    /**
     * 设置数据表的引擎
     * @param  [type] $table 表名
     * @param  string $value MyISAM/InnoDB/...
     * @return [type]        [description]
     */
    public function setTableEngine($table,$value='InnoDB')
    {    
        $this->tableExists($table);
        $engines=$this->getEngines();
        $newArr=[];
        foreach ($engines as $key => $engineMsgArr) {            
            if($engineMsgArr['Support']==='YES'||$engineMsgArr['Support']==='DEFAULT'){
                $newArr[]=strtolower($engineMsgArr['Engine']);
            }
        }

        if(!in_array(strtolower($value),$newArr)){
            $this->outputError('mysql目前不支持该引擎');
        }

        $sql="ALTER TABLE {$this->prefix}$table ENGINE = $value";
        $res=$this->pdo->exec($sql);
        $this->getPDOError();
        return $res;//返回受影响行数有多少数据就返回多少数字
    }




    /**
     * 获取自动提交的状态 1开启自动提交 0关闭自动提交
     * PDO::ATTR_AUTOCOMMIT  0
     * @return [type] [description]
     */
    public function getAttrAutoCommit()
    {
        return $this->pdo->getAttribute(PDO::ATTR_AUTOCOMMIT);
    }
    /**
     * 设置自动提交的状态 1开启自动提交 0关闭自动提交
     * PDO::ATTR_AUTOCOMMIT  0
     * @return [type] [description]
     */
    public function setAttrAutoCommit($value=true)
    {    
        $this->isBoolean();
        return $this->pdo->setAttribute(PDO::ATTR_AUTOCOMMIT,$value);
    } 

    /**
     * 获取当前mysql支持事务的引擎
     * @return [type] [description]
     */
    public function getTransactionEngine()
    {
        $sql="SELECT ENGINE FROM INFORMATION_SCHEMA.ENGINES WHERE SUPPORT IN ('YES','DEFAULT') AND TRANSACTIONS='YES'";
        $data=$this->query($sql);
        $this->getPDOError();
        return $data;
    }

    /**
     * 开启事务
     * @param  [type] $table [description]
     * @return [type]        [description]
     */
    public function beginTransaction($table){
        $this->tableExists($table);
        $engine=$this->getTableEngine($table);
        $engineLower=strtolower($engine);
        switch ($engineLower) {
            case 'innodb':
            case 'bdb'://5.1一下版本才支持 Berkley的别名
            case 'berkley'://5.1一下版本才支持
                return $this->pdo->beginTransaction();
                break;
            case 'myisam'://8.0被废弃
            case 'isam'://过时的存储引擎，现在由MyISAM取代
            case 'mrg_myisam':
            case 'merge'://MRG_MYISAM的别名
            case 'mrg_isam'://过时的存储引擎，现在由MERGE取代
            case 'csv':
            case 'performance_schema':
            case 'archive':
            case 'memory':
            case 'heap'://MEMORY正式地被确定为HEAP引擎
            case 'blackhole':
            case 'federated':
            case 'ndb':
            case 'example':
            case 'ndbcluster'://NDB别名
                $this->outputError("当前表引擎为$engine,目前不支持事务");
                break;    
            default:
                $this->outputError("当前表引擎为$engine,请核对是否支持事务");
                break;
        }
        
    }
    public function commit(){
        return $this->pdo->commit();
    }
      public function rollBack(){
        return $this->pdo->rollBack();
    }







    /**
     * 设置错误级别    
     * 0 ERRMODE_SILENT       默认模式，不主动报错，需要主动以 $pdo->errorInfo()的形式获取错误信息
     * 1 ERRMODE_WARNING      显示警告错误   引发 E_WARNING 错误，主动报错
     * 2 ERRMODE_EXCEPTION    主动抛出 exceptions 异常，需要以try{}cath(){}输出错误信息
     * 3 PDO::ATTR_ERRMODE
     * @param integer $value  错误级别的值 
     * @return boolean            成功返回true，失败返回false
     */
    public function setAttrErrMode($value=0)
    {
        if($value==1){
             $res=$this->pdo->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_WARNING);
        }elseif ($value==2) {
            $res=$this->pdo->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_EXCEPTION);
        }else{
            $res=$this->pdo->setAttribute(PDO::ATTR_ERRMODE,PDO::ERRMODE_SILENT);
        }
        return $res;
    }

    /**
     * 获取错误级别
     * @return integer 返回错误级别
     */
    public function getAttrErrMode()
    {
        return $this->getAttribute(PDO::ATTR_ERRMODE);
    }

    /**
     * 设置pdo属性值
     * @param integer $name  属性名
     * @param mixd $value    true or Exception  返回布尔值或抛出异常
     */
    public function setAttribute($name,$value)
    {
        $this->isInteger($name);
        try {
           $res=$this->pdo->setAttribute($name,$value);
           return $res;
        } catch (PDOException $e) {
            $this->outputError($e->getMessage());
        }
        
    }

    /**
     * /
     * @param   $name [description]
     * @return [type]       [description]
     */
    public function getAttribute($name)
    {        
        $this->isInteger($name);
        return $this->pdo->getAttribute($name);
    }


    public function isInteger($name){
        if(!is_int($name)){
            throw new Exception("Param Error: 第一个参数不是期望的整形");    
        }
    }
    public function isBoolean ($name){
        if(!is_bool($value)||$value!==1||$value!==0){
            throw new Exception("Param Error: 不是期望的布尔参数");
        }
    }

    /**
     * 是否开启长链接
     * 什么情况下使用长连接？
     * 不同的脚本的执行间距非常短，同时每个脚本都要操作数据库（Mysql：mysql_pconnect()）
     * @param  [type]  $value [description]
     * @return boolean        [description]
     */
    public function isAttrPersistent($value=false)
    {
        $this->isBoolean(); 
        return $this->pdo->setAttribute(PDO::ATTR_PERSISTENT,$value);
    }

    /**
     * 设置默认的数据提取模式
     * PDO::FETCH_ASSOC 2
     * @param integer $value [description]
     */
    public function setAttrDefaultFetchMode($value=PDO::FETCH_BOTH)
    {
        $this->isInteger();
        /*
            setFetchMode($value)
         */
        return $this->pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE,$value);
    }

    /**
     * 设置数据的提取模式 
     * @param integer $value [description]
     */
    public function setFetchMode($value=2)
    {
        $this->pdo->setFetchMode($value);    
    }






     /**
     * 输出错误信息
     * 
     * @param String $strErrMsg
     */
    private function outputError($strErrMsg)
    {    echo '<pre>';
        throw new Exception('MySQL Error: '.$strErrMsg);
    }

    /**
     * getPDOError 捕获PDO错误信息
     */
    private function getPDOError()
    {
        if ($this->pdo->errorCode() != '00000') {
            $arrayError = $this->pdo->errorInfo();
            $this->outputError($arrayError[2]);
        }
    }    

    public function dump($value='')
    {
        echo '<pre>';
        var_dump($value);        
    }



    public function aL($data,&$al,$level=0)
    {
        if(is_array( $data )){
            $level++;
            $al[] = $level;
            foreach($data as $v){
                $this->aL($v,$al,$level);
            }
        }
    }
    public function arrLevel($where)
    {    
        $this->al=[];//去掉缓存
        $this->aL($where,$this->al,$level=0);
        return max($this->al);
    }

}