php的pdo数据层mysql类

闲着在家没事儿，写着玩。。。

<?phpheader("Content-type:text/html;charset=utf-8");/** * Created by PhpStorm. * User: Administrator * Date: 2016/8/9 * Time: 11:48 */abstract class DB{    protected abstract function connect();    public abstract function query($sql);    public abstract function insert($arr);    public abstract function getALL();    public abstract function delete($key,$id);    public abstract function update($arr);}class pdoMysql extends DB{    private $host;    private $username;    private $password;    private $dbname;    private $table;    public $pdh;    private $where_sql = null;    private $table_fields = null;    private static $mysql = null;    final protected function __construct($host,$username,$password,$dbname,$table){        $this->host = $host;        $this->username = $username;        $this->password = $password;        $this->dbname = $dbname;        $this->table = $table;        $this->connect();    }    final public static function getInstance($host,$username,$password,$dbname,$taable){        if(self::$mysql instanceof self)            return self::$mysql;        else{            self::$mysql = new self($host,$username,$password,$dbname,$taable);            return self::$mysql;        }    }    final protected function connect(){        $this->pdh = new PDO('mysql:host='. $this->host .';dbname=' .$this->dbname , $this->username, $this->password);        if($this->pdh === null)            die('connect error');        $stmt = $this->pdh->prepare('DESC '.$this->table);        $stmt->execute();        $this->table_fields = $stmt->fetchAll(PDO::FETCH_COLUMN);        if($this->table_fields === null)            die('this table ' . $this->table . ' do not exists');        $this->query("set names utf8");    }    public function query($sql){        $res = $this->pdh->query($sql);        return $res;    }    protected function check_sql_arr($arr){        $key_arr = array_keys($arr);        foreach($key_arr as $v){            if(!in_array($v,$this->table_fields))                die('sql fields error');        }        return $arr;    }    public function insert($arr){        $arr = $this->check_sql_arr($arr);        $sql = 'insert into ' . $this->table . ' (' . implode(',',array_keys($arr)) . ')';        $sql .= ' values (\'';        $sql .= implode("','",array_values($arr));        $sql .= '\')';        $this->query($sql);    }    public function getALL(){        $res = $this->pdh->query("SELECT * FROM ". $this->table , PDO::FETCH_ASSOC);        return $res->fetchAll();    }    public function delete($key,$id){        $this->where($key, $id);        $sql = 'delete from ' . $this->table . ' where ' . $this->where_sql;        $this->query($sql);        $this->where_sql = null;    }    public function update($arr){        $arr = $this->check_sql_arr($arr);        if(!empty($this->where_sql))        {            $sql = 'update ' . $this->table .' set ';            foreach($arr as $k=>$v) {                $sql .= $k . "='" . $v ."',";            }            $sql = rtrim($sql,',');            $sql .= ' where ' .$this->where_sql;            $this->query($sql);        }        $this->where_sql = null;    }    public function where(){        $func_args_arr = func_get_args();        $key = array_intersect($func_args_arr,$this->table_fields);        unset($func_args_arr[array_search($key,$func_args_arr)]);        $key = array_pop($key);        $sign = array_intersect($func_args_arr,array('>','<','='));        unset($func_args_arr[array_search($sign,$func_args_arr)]);        $sign = array_pop($sign);        $num = array_pop($func_args_arr);        if($key && $num)        {            $this->where_sql .= $this->where_sql == null ? sprintf("(%s %s %d)",$key,$sign == null ? '=' : $sign,$num) : sprintf(" and (%s %s %d)",$key,$sign == null ? '=' : $sign,$num);        }else{            die('arguments error in pdoMysql::where()');        }    }    public function whereor(){        $func_args_arr = func_get_args();        $key = array_intersect($func_args_arr,$this->table_fields);        unset($func_args_arr[array_search($key,$func_args_arr)]);        $key = array_pop($key);        $sign = array_intersect($func_args_arr,array('>','<','=','like'));        unset($func_args_arr[array_search($sign,$func_args_arr)]);        $sign = array_pop($sign);        $num = array_pop($func_args_arr);        if($key && $num)        {            if(is_int($num))                $this->where_sql .= $this->where_sql == null ? sprintf("(%s %s %d)",$key,$sign == null ? '=' : $sign,$num) : sprintf(" or (%s %s %d)",$key,$sign == null ? '=' : $sign,$num);            else                $this->where_sql .= $this->where_sql == null ? sprintf("(%s %s '%s')",$key,$sign == null ? '=' : $sign,$num) : sprintf(" or (%s %s '%s')",$key,$sign == null ? '=' : $sign,$num);        }else{            die('arguments error in pdoMysql::where()');        }    }    public function find(){        if(!empty($this->where_sql))        {            $res = $this->pdh->query("SELECT * FROM ". $this->table . ' where ' . $this->where_sql, PDO::FETCH_ASSOC);            print_r($res->fetchAll());        }        $this->where_sql = null;    }}$pdoMysql = pdoMysql::getInstance(YOURHOST,USERNAME,PASSWORD,DBNAME,TABLENAME);/*where查询$pdoMysql->where('goods_id','>',8);$pdoMysql->where('goods_id','<',10);$pdoMysql->whereor('goods_name','like','两%');$pdoMysql->find();*//*update修改$pdoMysql->where('goods_id','=',100);$pdoMysql->update(array(    'goods_id' => 10    ));*//*insert插入$pdoMysql->insert(array(        'goods_id' => 100,        'goods_name' => 'insert_goods_name'    ));*//*delete删除$pdoMysql->delete('goods_id',100);*/