致命錯誤：調用成員函數結果錯誤

Question

這段代碼有什麼問題。收到此錯誤

Fatal error: Call to a member function result() on a non-object in /system/application/models/miscellaneousmodel.php on line 

function getSubCategories($categoryId){ 
     $this->db->select("CATEGORY_ID,SUB_CATEGORY_URL AS CATEGORY_URL, CATEGORY_DESC,ACTIVE_STATUS,SORT_ORDER"); 
     $whereCondition = $array = array('CATEGORY_ID' =>$categoryId);  
     $this->db->where($whereCondition); 
     $query = $this->db->get('TRN_SUB_CATEGORY');     
     return $query->result();  
    } 

正是這個錯誤，決心與現在下面的代碼，但

現在沒有表現出對SUB_CATEGORY_URL正確的別名AS CATEGORY_URL

ResultstdClass Object ([SUB_CAT_ID] => 1 [CATEGORY_ID] => 1 [CATEGORY_DESC] => EMU Meat [ACTIVE_STATUS] => A [SUB_CATEGORY_URL] => /categories/agriculture-products/emu-meat) 

$query = $this->db->query("SUB_CATEGORY_ID,SUB_CATEGORY_URL AS CATEGORY_URL, CATEGORY_DESC,ACTIVE_STATUS"); 
     $whereCondition = $array = array('CATEGORY_ID' =>$categoryId); 
     $this->db->where($whereCondition); 
     $query = $this->db->get("trn_sub_category"); 
     return $query->result(); 

這是我的表

CREATE TABLE IF NOT EXISTS `trn_sub_category` (
    `SUB_CAT_ID` int(10) unsigned NOT NULL AUTO_INCREMENT, 
    `CATEGORY_ID` int(10) unsigned NOT NULL, 
    `CATEGORY_DESC` varchar(250) NOT NULL, 
    `ACTIVE_STATUS` varchar(1) NOT NULL, 
    `SUB_CATEGORY_URL` varchar(300) NOT NULL, 
    PRIMARY KEY (`SUB_CAT_ID`) 
) 

Answer 1

嘗試

return $query->result_array(); 

Answer 2

讓儘量讓你這樣的功能：

function getSubCategories($categoryId){ 
     $select = "CATEGORY_ID,SUB_CATEGORY_URL AS CATEGORY_URL, CATEGORY_DESC,ACTIVE_STATUS,SORT_ORDER"; 
     $whereCondition = $array = array('CATEGORY_ID' =>$categoryId); 
     $this->db->select($select)->where($whereCondition); 

     $query = $this->db->get('trn_sub_category');     
     return $query->result();  
    } 

通常這正常工作與我，你可以嘗試一下，如果它的工作告訴我..