致命错误:调用成员函数结果错误 - Fatal error: Call to a member function result error

Fatal error: Call to a member function result error

这段代码有什么问题。收到此错误

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();    
    }

该错误现在已通过以下代码解决，但是

现在不显示SUB_CATEGORY_URL AS CATEGORY_URL的正确别名

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();

这是我的桌子

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`)
)

试试

return $query->result_array();

让我们尝试使你的函数像这样：

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();    
    }

通常这对我很好用，你能试试它并告诉我它是否有效..