Warum kann PHP keine Verbindung zu Orcle herstellen?

$config = array (

    'dbconfig' => 
          array (
            'db_host_name' => '192.168.2.197/orcl',
            'db_user_name' => 'zbkf',
            'db_password' => 'zbkf',
             
          ),
);

//返回值  
    $arr_result = array(); 
    $arr_result['result'] = 'false';  //true false 为黑名单
    $arr_result['callerid'] = $callerid;  
     
    //取数据库参数
    $db_host_name=$config['dbconfig']['db_host_name']; //'localhost/ORCL''
    $db_user_name=$config['dbconfig']['db_user_name'];//'asgr'
    $db_pwd=$config['dbconfig']['db_password']; //'asgr'

    //连接Oracle
    $conn = oci_connect($db_user_name,$db_pwd,$db_host_name);//oci_connect('asgr','asgr','localhost/ORCL');
    if (!$conn) { 
        $e = oci_error(); 
        //print htmlentities($e['message']); 
        //WriteLog("连接Oracle时出错,oci_connect(".$db_user_name.",".$db_pwd.",".$db_host_name.")  ".htmlentities($e['message']));
        $arr_result['result'] = 'false';
        echo json_encode($arr_result);  //默认为不是黑名单
        return;
    } 
    else {
        //echo("连接成功！");
        //$select = 'SELECT BL_TEL FROM CC_BLACKLIST'; // 查询语句 
        $select = "Select count(BL_Tel) from CC_BlackList where BL_Tel like '%" . $callerid . "%' and BL_SFQY='0' ";
        //WriteLog($select);
        $result_rows = oci_parse($conn, $select); // 配置SQL语句，执行SQL
        $row_count = oci_execute($result_rows, OCI_DEFAULT); // 行数  OCI_DEFAULT表示不要自动commit 
        //echo($row_count);
        if(!$row_count) { //没有行
            $e = oci_error($result_rows); 
            //echo htmlentities($e['message']); 
            //WriteLog("查询时出错或没有行！,oci_connect(".$db_user_name.",".$db_pwd.",".$db_host_name.")  ". $select."  ".htmlentities($e['message']));
            $arr_result['result'] = 'false';
            echo json_encode($arr_result);  //默认为不是黑名单
        } 
        /*
        //取每行每列值 
        while($row = oci_fetch_array($result_rows, OCI_RETURN_NULLS)) {
             if($row[0]==$callerid){
                $arr_result['result']='true';
                echo json_encode($arr_result);  //是黑名单
                exit;
             }
        }
        */
        $count=0;
        while($row = oci_fetch_array($result_rows, OCI_RETURN_NULLS)) {
            $count=$row[0];
            break;
        }
        //WriteLog($count);
        if($count>=1){
            $arr_result['result']='true';
        }
        else {
            $arr_result['result']='false';
        }
        echo json_encode($arr_result);  //默认为不是黑名单
    }