在活动记录代码点火器中选择 SELCT 内部

Question

我想计算时差 我已经尝试过在mysql上进行查询和查询工作

SELECT  *, CONCAT_WS(" ", date1, hour1) AS rhour1,  CONCAT_WS(" ", date2, hour2) AS rhour2, (SELECT TIMEDIFF(rhour2,rhour1) AS diffhour) from TABLE1

我使用codeigniter查询生成器在活动记录中写入：

$this->db->select('*, CONCAT_WS(" ", date1, hour1) AS rhour1,  CONCAT_WS(" ", date2, hour2) AS rhour2, (SELECT TIMEDIFF(rhour2,rhour1) AS diffhour)');
$this->db->from('table1');
$this->db->join('table2','table1.code_number = table2.code_number');    
$query = $this->db->get();

结果我无法获得值差异小时:(

我的代码活动记录有什么问题？

Answer 1

希望这会对您有所帮助：

注意：确保您添加了所有列名的表名，就像这样table1.code_number

$this->db->select('*');
$this->db->select('CONCAT_WS(" ", date1, hour1) AS rhour1');
$this->db->select('CONCAT_WS(" ", date2, hour2) AS rhour2');
$this->db->select('TIMEDIFF(CONCAT_WS(" ", date2, hour2),CONCAT_WS(" ", date1, hour1)) AS diffhour');
$this->db->from('table1');
$this->db->join('table2','table1.code_number = table2.code_number');    
$query = $this->db->get();