1

我有一张表，下面给出了记录。我想要的是单选查询，它按 mediaid 显示第一条记录最小值第二条记录平均值和第三条记录最大值组？

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

===数据库详细信息

== 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

===数据库详细信息

== Dumping data for table tblmedia

|51|Tplanin
|52|Casfung
|53|Knee Surgery
|54|Doriglen
|55|Colymonas
|56|inem
|57|Casfungtest
4

1 回答 1

8

如果您想要单行中的值，您可以这样做：

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

如果您希望它们在单独的行中，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;

见SQL Fiddle with Demo

编辑 #1，使用添加的示例数据：

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

请参阅带有演示的 SQL Fiddle

于 2012-09-17T19:29:32.290 回答