PHP WITH ORACLE：查询为某些表选择不起作用

I am connected to a database using oci8 and codeigniter. some queries work for some tables and some not.

I have no idea why this should be

--------- FIRST CASE -------

This is my query

public function obtenemos_data3(){
 $conection_remote = $this->load->database('conection_remote', TRUE);
 $sql="select * from ITEM_MASTER WHERE SKU_ID='169989X'";
 $statement=oci_parse($conection_remote->conn_id,$sql);
 oci_execute($statement,OCI_DEFAULT);

 $num_rows = oci_fetch_all($statement, $result);
 echo $num_rows." numero de filas del resultado";

 oci_free_statement($statement);
 oci_close($conection_remote->conn_id);
 return $result;          

}

Result by PHP

Result by program plsqldev

------ SECOND CASE ------

Just change query

    public function obtenemos_data3(){
     $conection_remote = $this->load->database('conection_remote', TRUE);
     $sql="select CASE_NBR from CASE_HDR WHERE CASE_NBR='600008103900000156'";
     $statement=oci_parse($conection_remote->conn_id,$sql);
     oci_execute($statement,OCI_DEFAULT);

     $num_rows = oci_fetch_all($statement, $result);
     echo $num_rows." numero de filas del resultado <br>";

     oci_free_statement($statement);
     oci_close($conection_remote->conn_id);
     return $result;          

    }

Result by php

Result by programa plsqldev

I would like to know what might be happening. Thank you in advance for your help