Question

我有一个SQL查询，通过它我从三个表中检索所有匹配的logtime，每当列st1_vs1_bag4_onoff =＆＃39; 0＆＃39;时，那么不同表st1_vs1_bag4_rb中的相应列将显示其值，否则为0将显示在st1_vs1_bag4_rb中。

还检索了beam_current列。现在我只想显示那些非常靠近beam_current 10,20,30 ...直到220的行。只有一行对应于每个值。

我有一个SQL查询，它检索beam_current接近10,20,30到220的行，但是检索了与每个值对应的许多行。

我的SQL查询是：

select 
    b.LOGTIME, b.beam_current, b.beam_energy,
    case 
        when a.st1_vs1_bag1_onoff = 0 and a.logtime = c.logtime 
           then c.st1_vs1_bag1_rb 
           else 0 
    end as st1_vs1_bag1_rb,
    case
        when a.st1_vs1_bag2_onoff = '0' and a.logtime = c.logtime 
           then c.st1_vs1_bag2_rb 
           else '0' 
    end as st1_vs1_bag2_rb ,
    case 
        when a.st1_vs1_bag3_onoff = '0' and a.logtime = c.logtime 
           then c.st1_vs1_bag3_rb 
           else '0' 
    end as st1_vs1_bag3_rb,
    case
        when a.st1_vs1_bag4_onoff = '0' and a.logtime = c.logtime 
           then c.st1_vs1_bag4_rb 
           else '0' 
    end as st1_vs1_bag4_rb ,
    case 
        when a.st1_vs1_bag5_onoff = '0' and a.logtime = c.logtime 
           then c.st1_vs1_bag5_rb 
           else '0' 
    end as st1_vs1_bag5_rb ,
    case
        when a.st1_vs1_bag6_onoff = '0' and a.logtime = c.logtime 
           then c.st1_vs1_bag6_rb 
           else '0' 
    end as st1_vs1_bag6_rb ,
    case
        when a.st1_vs1_bag7_onoff = '0' and a.logtime = c.logtime 
           then c.st1_vs1_bag7_rb 
           else '0' 
    end as st1_vs1_bag7_rb ,
    case
        when a.st1_vs1_bag8_onoff = '0' and a.logtime = c.logtime 
           then c.st1_vs1_bag8_rb 
           else '0' 
    end as st1_vs1_bag8_rb 
from 
    INDUS2_BDS.dbo.DCCT b  
inner join
    (main_vacuum_analog c 
inner join 
    main_vacuum_status a on c.logtime = a.logtime) ON a.LOGTIME = b.LOGTIME 
           and (cast(cast(b.beam_current as decimal) % 10.0 as real) <= 0.01 ) OR (cast( cast     (b.beam_current as decimal)% 10.0 as real)>= 9.99))
and (cast(cast(b.beam_current as decimal)as real) >= 9.99) -- to set the lower limit of 9.99
and(cast(cast(b.beam_current as decimal)as real) <= 220.10)
and b.logtime between '2014-10-10 07:17:00' and '2014-10-10 08:46:00'

这将检索大约50行，对应于接近10的值，依此类推，这样就可以检索大约459行的所有值，直到220.我可以检索最接近每个值的一行，这样我就能够只检索22行？

编辑1

通过此查询输出的示例是：

enter image description here

我想要一行其beam_current值最接近10的行，但我有很多行，其值接近10.如何解决这个问题??

Answer 1

根据您的评论，您似乎需要预处理DCCT表，以便为LogTime中的组（10,20,30,40 ......）提供最大价值。

如果我的假设是正确的，你需要进入子查询，它给你带有LogTime的Beam_Current，然后加入你的其他表。

希望以下代码有所帮助。

declare @DCCT table (LOGTIME datetime, beam_current varchar(10), beam_energy numeric(10,5))

insert into @DCCT (LOGTIME, beam_current, beam_energy)
select '2014-10-10 07:29:31', '9.5',551.0052
union all
select '2014-10-10 07:29:32', '9.61',550.9918
union all
select '2014-10-10 07:29:33', '9.91',551.0052
union all
select '2014-10-10 07:29:34', '9.78',550.9918
union all
select '2014-10-10 07:29:35', '19.5',551.0052
union all
select '2014-10-10 07:29:36', '12.61',550.9918
union all
select '2014-10-10 07:29:37', '15.91',551.0052
union all
select '2014-10-10 07:29:38', '35.5',551.0052
union all
select '2014-10-10 07:29:39', '37.61',550.9918
union all
select '2014-10-10 07:29:40', '210.91',551.0052
union all
select '2014-10-10 07:29:41', '216.91',551.0052


if OBJECT_ID('tempdb..#Temp_DCCT') is not null
    drop table #Temp_DCCT

select *
, case
    when cast(beam_current as real) < 10 then 1
    when cast(beam_current as real) >= 10 and cast(beam_current as real) < 20 then 2
    when cast(beam_current as real) >= 20 and cast(beam_current as real) < 30 then 3
    when cast(beam_current as real) >= 30 and cast(beam_current as real) < 40 then 4
    when cast(beam_current as real) >= 40 and cast(beam_current as real) < 50 then 5
    -- add all other groups here .....
    else 6  -- change else to last group
    end as beam_current_grp
into #Temp_DCCT
from @DCCT
where LOGTIME between '2014-10-10 07:17:00' and '2014-10-10 08:46:00'


select *
from
(
    select *
        , ROW_NUMBER() over (partition by beam_current_grp order by beam_current_grp ASC, beam_current DESC) as rownum
    from #Temp_DCCT
) T_DCCT
where rownum = 1

我用于生成DCCT数据的数据的结果将是：

LOGTIME                     beam_current    beam_energy     beam_current_grp    rownum
2014-10-10 07:29:33.000     9.91            551.00520       1                   1
2014-10-10 07:29:35.000     19.5            551.00520       2                   1
2014-10-10 07:29:39.000     37.61           550.99180       4                   1
2014-10-10 07:29:41.000     216.91          551.00520       6                   1

如何仅查找最接近给定列值的行

1 个答案: