php为什么连接不上orcle

$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
 }