Question

如何通过未保存在数据库中的字段对查询结果进行分组。

例如，我想按照开始时间和结束时间减去的持续时间对结果进行分组。

这是我如何找出持续时间

date1= $row_TicketRS['CloseDate']; 
$date2 = $row_TicketRS['OpenDate'];

$diff = abs(strtotime($date2) - strtotime($date1)); 

$days = floor(($diff - $years * 365*60*60*24 - $months*30*60*60*24)/ (60*60*24));


if ( $days > 0)

{

$time1 = $row_TicketRS['OpenTime'];
$time2= $row_TicketRS['CloseTime'];

$t1=($time1); 
$t2=($time2);

$end=('14:30');
$start=('07:30');

$n = $end- $t1;

$n2 = $t2- $start;

$Hours2 = floor(($n+$n2)+(($days-1)*7));

echo   $Hours2.' Hours';

但知道我不知道如何将其添加到查询

这是我的查询

$strQuery = "SELECT count(`ticket`.TicketID) as TotOutput, department.`DeptName` FROM `ticket`, `user`, department where ticket.OwnerID = user.EmpNo and  user.`DepartmentID` = department.`DepartmentID` and OpenDate between'".$DateFrom."' And '".$DateTo."'"

Answer 1

最好有详细信息，但派生表/内联视图允许您按计算值进行分组：

  SELECT x.duration, 
         COUNT(*)
    FROM (SELECT t.col, 
                 t.end_time - t.start_time AS duration
            FROM YOUR_TABLE t) x
GROUP BY x.duration

Answer 2

如何使用如下别名将该计算值添加到查询中：

SELECT some_fields, end - start AS duration FROM table ORDER BY duration

Answer 3

不要为隐藏列添加别名，直接使用

〔实施例：

SELECT id, FLOOR(value/100)
  FROM tbl_name
  GROUP BY id, FLOOR(value/100);

Reference

MySQL允许GROUP BY中的表达式条款，所以别名是不必要的：

按非数据库字段分组

3 个答案: