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Php codeigniter:无法使用联接检索数据_Php_Mysql_Codeigniter_Join - Fatal编程技术网

Php codeigniter:无法使用联接检索数据

Php codeigniter:无法使用联接检索数据,php,mysql,codeigniter,join,Php,Mysql,Codeigniter,Join,目前我有外键thirdsmu id值,现在我想得到 thirdsubmenu\u namefromthirdmenutable,submenu\u namefromsubmenutable,menu\u namefrommain menutable 请帮我解决这个问题。 我尝试了下面的代码,但我的型号代码不正确。它不显示我的数据 我的数据库表结构 1)Table: mainmenu --------------- mainmenu_id PK(primary key)

目前我有外键thirdsmu id值,现在我想得到

thirdsubmenu\u name
from
thirdmenu
table,
submenu\u name
from
submenu
table,
menu\u name
from
main menu
table

请帮我解决这个问题。 我尝试了下面的代码,但我的型号代码不正确。它不显示我的数据

我的数据库表结构

   1)Table: mainmenu
    ---------------
     mainmenu_id   PK(primary key)
     menu_name     ..... 

    2)Table: submenu
    -------------------
     submenu_id     PK
     mainmenu_id    FK (foreign key refrences mainmenu table)
     submenu_name   ..... 


    3)Table: thirdsubmenu
    --------------------
      thirdsubmenu_id     PK
      submenu_id          FK (foreign key refrences submenu table)
      thirdsubmenu_name     ........


    4)Table: thirdsmcontentdetails
    --------------------
      thirdsmcontent_id   PK
      thirdsubmenu_id     FK (foreign key refrences thirdsubmenu table)
      content              ......
在我的控制器中

 $thirdsubmenu_id = $this->uri->segment(4);

   $data['main_menuname'] = $this->thirdsmcontentdetailsmodel->getMainMenuNameOfSubmenu($thirdsubmenu_id); 
在我的车型中

 //---------------------------get Main Menu Name by Menu id-----------------------------------
 function getMainMenuNameOfSubmenu($thirdsubmenu_id)
  {     
         $this->load->database();
         $query = $this->db->join('thirdsubmenu','thirdsubmenu.submenu_id = thirdsmcontentdetails.submenu_id')->get_where('thirdsubmenu',array('thirdsubmenu_id'=>$thirdsubmenu_id));  
         return $query->row('menu_name'); 
  }
获取错误:

    A Database Error Occurred

    Error Number: 1066

    Not unique table/alias: 'thirdsubmenu'

    SELECT * FROM (`thirdsubmenu`) JOIN `thirdsubmenu` ON `thirdsubmenu`.`submenu_id` = `thirdsmcontentdetails`.`submenu_id` WHERE `thirdsubmenu_id` = '1'

    Filename: D:\xampp\htdocs\system\database\DB_driver.php

    Line Number: 330

您将
FROM
JOIN
定义为
thirdsubmenu
,这是不可能的,也是没有意义的。 或使用:

$this->db->join('thirdsubmenu','thirdsubmenu.submenu_id = thirdsmcontentdetails.submenu_id');
$query = $this->db->get_where('thirdsmcontentdetails',array('thirdsubmenu_id'=>$thirdsubmenu_id));
或:


请查看,以了解如何定义联接。

您正在将
联接定义为
第三个子菜单
,这是不可能的,也是没有意义的。
或使用:

$this->db->join('thirdsubmenu','thirdsubmenu.submenu_id = thirdsmcontentdetails.submenu_id');
$query = $this->db->get_where('thirdsmcontentdetails',array('thirdsubmenu_id'=>$thirdsubmenu_id));
或:


请查看以了解如何定义联接。

我认为您在“选择此处”中使用了错误的表。@KishorSubedi您能为我的问题发布一个答案吗。你是尼泊尔人吗?是的,我是。好的,我会发布我的答案。我想你在“选择这里”中使用了错误的表格。@KishorSubedi你能发布我问题的答案吗。你是尼泊尔人吗?是的,我是。好的,我会发布我的答案。