Question

表格格式：表名类别：

      id       title
   -----------------
      1          xyz
      2          abc

表名子类别：

     id        category_id    start_date      status
 ----------------------------------------------------------
     1             1            2016-11-03       1
     2             1            2016-11-09       1
     3             2            2016-10-03       1
     4             3            2016-12-03       1
     5             3            2016-12-05       1
     6             5            2016-12-06       1

查询：

      $date = date('Y-m-d');
      $this->db->select('*');
      $this->db->where('status',1);
      $this->db->where('start_date >=',$date);
      $this->db->order_by('start_date', 'asc');
      $this->db->group_by('category_id');
      $this->db->limit(4);
      $query = $this->db->get('subcategory');
      return $query->result();

我的问题是：我希望结果为subcategory_id 1,4,6。但是group_by和order by不起作用。

错误：

SELECT列表不在GROUP BY子句中，并且包含nonaggregated 列'dbname.subcategory.id'，它在功能上不依赖于 GROUP BY子句中的列;这是不相容的 sql_mode = only_full_group_by SELECT * FROM（subcategory）WHERE status = 1 AND start_date＆gt; ='2016-11-03'GROUP BY category_id ORDER BY start_date asc LIMIT 4

Answer 1

更改您的查询

首先按顺序排列

$date = date('Y-m-d');
$this->db->select('*');
$this->db->where('status',1);
$this->db->where('start_date >=',$date);
$this->db->group_by('category_id');
$this->db->order_by('start_date', 'asc');
$this->db->limit(4);
$query = $this->db->get('subcategory');
return $query->result();

或者在$query之后执行此操作来打印查询，并在数据库中检查相同内容：

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

Answer 2

$date = date('Y-m-d');
$this->db->select('*');
$this->db->group_by('category_id');
$this->db->limit(4);
$query = $this->db->get("(SELECT * FROM subcategory where status=1 and start_date>='$date' order by start_date) as subcategory");
return $query->result();

由不在php codeigniter工作的排序和分组？

2 个答案: