Question

与其他帖子相比，我有不同的情况。我有两个表，如：

和的类别

现在，水果，零食，酱汁，午餐在子订单中列为类别表的ID。例如，如果Fruits is 1然后从类别表中，水果名称是Apple。我想从类别表列中获取其ID列在订阅表中的那些食物的名称：的 ITEMNAME

我正在使用codeigniter并尝试使用连接，但我没有看到任何值。

$this->db->select('*');
        $this->db->from('subsscription');
        $this->db->join('addschool','addschool.id=subsscription.schoolid');
        $this->db->join('user','user.id=subsscription.studentid');
        $this->db->join('category As u1','u1.id=subsscription.Fruits', 'left OUTER');

         $this->db->join('category As u2','u2.id=subsscription.snack', 'left OUTER');
         // $this->db->where('subsscription.snack >', '0');
        $this->db->join('category As u3','u3.id=subsscription.sauce', 'left OUTER');

         $this->db->join('category As u4','u4.id=subsscription.lunchdrink', 'left OUTER');

        $this->db->join('category As u5','u5.id=subsscription.icypole', 'left OUTER');

        $this->db->join('category As u6','u6.id=subsscription.lunch', 'left OUTER');
        // $this->db->where('subsscription.Fruits','category.id');
         // $this->db->group_by('subsscription.id');


        $query = $this->db->get();

        //echo $this->db->last_query();

        if($query->num_rows() > 0)
        {
            return $query->result();
        }
        else
        {
            return false;
        }

我的输出要求应该是：苹果，草莓牛奶，其中Apple的行ID是 1 ，草莓牛奶的行ID是 4 。

Answer 1

我无法通过SELECT（''）使其工作。我可能是错的，它经常发生，但我认为你不能这样做。以下对我有用。如果其他人有一个答案实际上只是抓住所有表中的所有内容，请随时添加它。

我也离开了学校的桌子，所以你必须重新学习。我用相关的信息创建了表格，并且不想制作那个。

    $this->db->select('subsscription.id AS sub_id, user.name, u1.itemname AS fruit, u2.itemname AS snack, u3.itemname AS sauce, u4.itemname AS lunchdrink, u5.itemname AS icypole, u5.itemname AS lunch');
    $this->db->from('subsscription');
    $this->db->join('user','user.id=subsscription.studentid', 'JOIN');
    $this->db->join('category As u1','subsscription.Fruits=u1.id', 'LEFT OUTER');
    $this->db->join('category As u2','subsscription.snack=u2.id', 'LEFT OUTER');
    $this->db->join('category As u3','subsscription.sauce=u3.id', 'LEFT OUTER');
    $this->db->join('category As u4','subsscription.lunchdrink=u4.id', 'LEFT OUTER');
    $this->db->join('category As u5','subsscription.icypole=u5.id', 'LEFT OUTER');
    $this->db->join('category As u6','subsscription.lunch=u6.id', 'LEFT OUTER');
    $query = $this->db->get();
    if($query->num_rows() > 0) {
        foreach($query->result() AS $row) {
            print '<pre>' . print_r($row, TRUE) . '</pre>';
        }
    }

这个的输出是：

stdClass Object
(
    [sub_id] => 1
    [name] => Betty
    [fruit] => Apple
    [snack] => 
    [sauce] => 
    [lunchdrink] => Strawberry Milk
    [icypole] => 
    [lunch] => 
)
stdClass Object
(
    [sub_id] => 2
    [name] => John
    [fruit] => Banana Bread
    [snack] => 
    [sauce] => Apple
    [lunchdrink] => 
    [icypole] => Strawberry Milk
    [lunch] => Strawberry Milk
)

我显然使用随机值。

如何从模态连接连接值

1 个答案: