连接3个表codeigniter php

我有三张桌子，客人信息，pg公司，用户档案

在来宾\用户\信息中有两列：

g_uid | company_id

company_id | user_id

id |user_email

在pg_中，公司有两列：

g_uid | company_id

company_id | user_id

id |user_email

在用户配置文件中，有两列：

g_uid | company_id

company_id | user_id

id |user_email

---

这里我想从

user\u profile中获取
user\u email
。我
have
g\u uid
值（在
guest\u user\u info
表中）。我想从guest\u user\u info中获取公司id并与
pg\u company
表匹配，在那里我可以得到用户id。然后在
user\u profile
表中用id匹配
user\u id
。最后，我需要
user\u email
从
user\u profile
表中找到
user\u id
这是一个简单的问题，您只需要使用CodeIgniter中的主动查询就可以加入

$this->db->select("UP.id", "UP.user_email");
$this->db->from("guest_user_info AS GU");
$this->db->join("pg_company AS PC", "PC.company_id=GU.company_id");
$this->db->join("user_profile AS UP", "UP.id=PC.user_id");
$this->db->where("GU.g_uid", $guid);
$query = $this->db->get();

return $query->result();

在上面的代码中，
$guid
您必须提供您所拥有的

另外，请查看以下链接：



读完这篇文章，你会得到很多东西

   Check bellow code it`s working fine and  common model function also 
    supported more then one join and also supported  multiple where condition
 order by ,limit.it`s EASY TO USE and REMOVE CODE REDUNDANCY.

   ================================================================
    *Album.php
   //put bellow code in your controller
   =================================================================

    $album_id='';//album id 

   //pass join table value in bellow format
    $join_str[0]['table'] = 'pg_company';
    $join_str[0]['join_table_id'] = 'pg_company.company_id';
    $join_str[0]['from_table_id'] = 'guest_user_info.company_id';
    $join_str[0]['join_type'] = '';//set join type

    $join_str[1]['table'] = 'user_profile';
    $join_str[1]['join_table_id'] = 'user_profile.id';
    $join_str[1]['from_table_id'] = 'guest_user_info.user_id';
    $join_str[1]['join_type'] = '';


    $selected ="guest_user_info.*,user_profile.user_name,pg_company.name";
    $condition_array=array('guest_user_info.g_uid' => $g_uid);     
   $albumData= $this->common->select_data_by_condition('guest_user_info', $condition _array, $selected, '', '', '', '', $join_str);
                               //call common model function

    if (!empty($albumData)) {
        print_r($albumData); // print album data
    } 

 =========================================================================
   Common.php
    //put bellow code in your common model file
 ========================================================================

   function select_data_by_condition($tablename, $condition_array = array(), $data = '*', $sortby = '', $orderby = '', $limit = '', $offset = '', $join_str = array()) {
    $this->db->select($data);
    //if join_str array is not empty then implement the join query
    if (!empty($join_str)) {
        foreach ($join_str as $join) {
            if ($join['join_type'] == '') {
                $this->db->join($join['table'], $join['join_table_id'] . '=' . $join['from_table_id']);
            } else {
                $this->db->join($join['table'], $join['join_table_id'] . '=' . $join['from_table_id'], $join['join_type']);
            }
        }
    }

    //condition array pass to where condition
    $this->db->where($condition_array);


    //Setting Limit for Paging
    if ($limit != '' && $offset == 0) {
        $this->db->limit($limit);
    } else if ($limit != '' && $offset != 0) {
        $this->db->limit($limit, $offset);
    }
    //order by query
    if ($sortby != '' && $orderby != '') {
        $this->db->order_by($sortby, $orderby);
    }

    $query = $this->db->get($tablename);
    //if limit is empty then returns total count
    if ($limit == '') {
        $query->num_rows();
    }
    //if limit is not empty then return result array
    return $query->result_array();
}