请参阅SQL Fiddle with Demo

Question

我有一张下面给出记录的表格。我想要的是单一选择查询，它显示了mediaid的第一记录最小第二记录平均值和第三记录最大值组？

trans_id      playtime       mediaid(F.K.) 
--------      --------       -------------
1              32             2
2              65             2
3              45             3
4              55             4
5              60             3
6              78             2
7              45             4
8              35             3

结果应该看起来像

 playtime       mediaid(F.K.) 
   --------       -------------
    32             2             (Min value)
    58.33          2             (avg value)
    78             2             (Max value)
    35             3             (Min value)
    46.66          3             (avg value)
    60             3             (Max value)
    45             4             (Min value)
    50             4             (avg value)
    55             4             (max value)

这是我给出结果的真实查询，但这不是由medtitle

安排的

select  t.medTitle as 'Media',
    min(TIMESTAMPDIFF(SECOND,s.dmtViewStart,s.dmtViewEnd))platime
        from dbedetailing.tblmedia t
        left outer join dbedetailing.tbldoctormediatracktest s on s.dmtMedId = t.medId 
        GROUP BY t.medTitle
        union all
        select  t.medTitle as 'Media',
    avg(TIMESTAMPDIFF(SECOND,s.dmtViewStart,s.dmtViewEnd))platime
        from dbedetailing.tblmedia t
        left outer join dbedetailing.tbldoctormediatracktest s on s.dmtMedId = t.medId 
        GROUP BY t.medTitle
        union all
        select  t.medTitle as 'Media',
    max(TIMESTAMPDIFF(SECOND,s.dmtViewStart,s.dmtViewEnd))platime
        from dbedetailing.tblmedia t
        left outer join dbedetailing.tbldoctormediatracktest s on s.dmtMedId = t.medId 
        GROUP BY t.medTitle ;

这是我给出结果的真实查询，但这不是由medtitle

安排的

===数据库dbedetailing

==表tbldoctormediatracktest的表结构

|------
|Column|Type|Null|Default
|------

    |//**dmtId**//|int(10)|No|
    |dmtDocId|int(10)|No|
    |dmtMedId|int(10)|No|
    |dmtViewingDate|datetime|No|
    |dmtViewStart|datetime|Yes|NULL
    |dmtViewEnd|datetime|Yes|NULL
    |dmaIsActive|enum('0', '1')|No|
    |insDate|datetime|No|
    |modDate|datetime|No|
    == Dumping data for table tbldoctormediatracktest
  Medid    dmtViewStart         dmtViewEnd
    |56|2012-08-24 11:41:14|2012-08-24 11:41:20
    |52|2012-08-24 11:41:24|2012-08-24 11:42:12
    |56|2012-08-24 11:41:14|2012-08-24 11:41:20
    |52|2012-08-24 11:41:24|2012-08-24 11:42:00
    |53|2012-08-25 12:32:27|2012-08-25 12:32:42
    |55|2012-08-27 06:48:51|2012-08-27 06:49:19
    |53|2012-08-27 06:49:25|2012-08-27 06:49:42
    |53|2012-08-28 02:56:16|2012-08-28 02:56:47
    |54|2012-08-28 02:57:58|2012-08-28 02:58:10
    |52|2012-08-28 05:48:14|2012-08-28 05:49:03
    |55|2012-08-28 07:16:00|2012-08-28 07:17:11
    |52|2012-08-22 04:03:00|2012-08-22 04:03:55
    |56|2012-08-28 07:16:00|2012-08-28 07:17:22
    |56|2012-08-23 09:00:00|2012-08-23 09:02:00
    |53|2012-08-16 04:00:00|2012-08-16 04:01:01
    |54|2012-08-20 12:33:00|2012-08-20 12:34:14
    |55|2012-08-16 04:00:20|2012-08-16 04:01:01
    |52|2012-08-20 12:31:00|2012-08-20 12:31:14
    |54|2012-08-20 12:33:14|2012-08-20 12:34:14
    |55|2012-08-20 12:48:00|2012-08-20 12:49:14
    |56|2012-08-20 12:33:00|2012-08-20 12:34:14
    |53|2012-08-20 12:43:00|2012-08-20 12:44:14
    |54|2012-08-20 12:33:00|2012-08-20 12:34:45
    |55|2012-08-20 12:33:00|2012-08-20 12:34:34
    |56|2012-08-20 12:33:00|2012-08-20 12:34:23
    |52|2012-08-20 12:33:00|2012-08-20 12:34:18
    |53|2012-08-20 12:33:00|2012-08-20 12:34:56
    |54|2012-08-20 12:33:00|2012-08-20 12:33:56
    |56|2012-08-20 12:33:00|2012-08-20 12:33:14
    |56|2012-08-20 12:33:00|2012-08-20 12:34:14



===Database dbedetailing

== Table structure for table tblmedia

|------
|Column|Type|Null|Default
|------
|//**medId**//|int(10)|No|
|medTitle|varchar(250)|No|
|medDesc|varchar(250)|No|
|medPath|varchar(250)|No|
|medType|int(10)|No|
|medSpeciality|int(10)|No|
|medProduct|int(10)|No|
|medIsActive|enum('0', '1')|No|
|insDate|datetime|No|
|modDate|datetime|No|
== Dumping data for table tblmedia

===数据库dbedetailing

== Dumping data for table tblmedia

|51|Tplanin
|52|Casfung
|53|Knee Surgery
|54|Doriglen
|55|Colymonas
|56|inem
|57|Casfungtest

Answer 1

如果您希望将值放在一行中，则可以执行以下操作：

select max(playtime), min(playtime), avg(playtime)
from yourtable
group by mediaid;

如果您希望它们位于不同的行中，请使用UNION ALL：

select max(playtime) playtime, mediaid, 'Max' Type
from yourtable
group by mediaid
union all
select min(playtime) playtime, mediaid, 'Min'
from yourtable
group by mediaid
union all
select avg(playtime) playtime, mediaid, 'Avg'
from yourtable
group by mediaid
order by mediaid, playtime;

请参阅SQL Fiddle with Demo

编辑＃1，使用您添加的示例数据：

select m.medTitle, 
  min(TIMESTAMPDIFF(SECOND, s.dmtViewStart, s.dmtViewEnd)) playtime
from tbldoctormediatracktest s
left join tblmedia m
  on s.MedId = m.MedId
group by m.medTitle
union all

select m.medTitle, 
  avg(TIMESTAMPDIFF(SECOND, s.dmtViewStart, s.dmtViewEnd)) playtime
from tbldoctormediatracktest s
left join tblmedia m
  on s.MedId = m.MedId
group by m.medTitle
union all

select m.medTitle, 
  max(TIMESTAMPDIFF(SECOND, s.dmtViewStart, s.dmtViewEnd)) playtime
from tbldoctormediatracktest s
left join tblmedia m
  on s.MedId = m.MedId
group by m.medTitle
order by medTitle,  playtime

如何从不同行的mysql表中获取min max和average？

1 个答案:

请参阅SQL Fiddle with Demo

请参阅SQL Fiddle with Demo