Работа с PDO

<?php
class Database{
 public $isConn;
 protected $datab;
 //connect to db
 public function __construct(#username="root", $password="", $host="localhost", $dbname="Database", $options=[]){
 $this->isConn=TRUE; // строка, содержащая ошибку
 try{
 $_this->datab=new PDO ("sqlsrv:Server= {$host}; dbname={$dbname}; charset=utf8", $username, $passwd, $options);
 $_this->datab->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXEPTION);
 $_this->datab->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
 } catch (PDOException $e) {
 throw new Exception($e->getMessage());
 
 }
 }
 //disconnect from db
 public function Disconnect(){
 $_this->datab=NULL;
 $_this->isConn=FALSE;
 }
 //get row
 public function getRow($query, $params=[]){
 try {
 $stmt=$_this->datab->prepare($query);
 $stmt->execute($params);
 return $stmt->fetch();
 } catch (PDOException $e){
 throw new Exception($e->getMessage());
 }
 }
 //get rows
 public function getRows($query, $params=[]){
 try {
 $stmt=$_this->datab->prepare($query);
 $stmt->execute($params);
 return $stmt->fetchAll();
 } catch (PDOException $e){
 throw new Exception($e->getMessage());
 }
 }
 //insert row
 public function insertRow($query, $params=[]){
 try {
 $stmt=$_this->datab->prepare($query);
 $stmt->execute($params);
 return TRUE;
 } catch (PDOException $e){
 throw new Exception($e->getMessage());
 }
 }
 //update row
 public function updateRow($query, $params=[]){
 $_this->insertRow($query, $params);
 }
 //delete row
 public function deleteRow($query, $params=[]){
 $_this->insertRow($query, $params);
 }
}
?>