CODEWITHSUNDEEP
sqlsql-serverdistinct
KeetsScrimalittle
KeetsScrimalittle

Reputation: 99

Select only first row of specify distinct results from one column only

I am trying to create a query that will get results of last software usage time per device.

In the table there are columns for filename and the starttime for each device. The issue I am running into is I only care about the latest start time for each device but the table will have multiple rows due to multiple recorded start times. Is there a way I can only get distinct results based on the device name? I can sort them by the start time, then device name to sort it with the latest but I want to remove the duplicate rows for each machine. I have looked at similar posts that use a subselect with row_number() (order by sud.StartTimeLocal) as rn but when I tried this it just returned one row. I am creating this for a report and would prefer to find a way to only return the row with latest time for each machine instead of trying group them in the report.
Here is the query I have:

declare @ProductName as nvarchar(250) = 'Visio'

select
sy.resourceid,
sy.name0 as 'DeviceName',
sud.FileName,
sud.FileDescription,
case
    substring(sud.FileVersion,1,2)
    when '16' then (Sud.FileDescription + ' 2016')
    when '15' then (Sud.FileDescription + ' 2013')
    when '14' then (Sud.FileDescription + ' 2010')
    end as 'Product',
sud.FileVersion,
sud.StartTimeLocal as 'LastExecuted'

from v_R_system sy
left join v_GS_SoftwareUsageData sud on sy.ResourceID = sud.ResourceID
where sud.FileName in (
 (@ProductName + '.EXE')
 )
and sud.StartNotCaptured != 1

order by sud.StartTimeLocal desc,sud.FileName,sy.Name0

Here is an example of the results i get

DeviceName      FileName    FileDescription Product                 FileVersion      LastExecuted
Machine Name1   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.4993.1001      4/29/2020 10:07
Machine Name1   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.4993.1001      4/29/2020 10:07
Machine Name2   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.4954.1000      4/28/2020 11:01
Machine Name3   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.11929.20648    4/28/2020 8:46
Machine Name3   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.11929.20648    4/27/2020 16:20
Machine Name3   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.11929.20648    4/27/2020 16:15
Machine Name3   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.11929.20648    4/27/2020 15:25
Machine Name3   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.11929.20648    4/27/2020 12:30
Machine Name3   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.11929.20648    4/27/2020 11:51
Machine Name3   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.11929.20648    4/27/2020 11:34
Machine Name3   VISIO.EXE   Microsoft Visio Microsoft Visio 2016    16.0.11929.20648    4/27/2020 8:04

Upvotes: 0

Views: 65

Answers (1)

Gordon Linoff
Gordon Linoff

Reputation: 1269793

If I had to speculate, you want one matching row from v_GS_SoftwareUsageData for each row in the first table. Probably the best method is cross apply:

select sy.resourceid, sy.name0 as DeviceName, sud.FileName, sud.FileDescription,
       (case left(sud.FileVersion,2)
            when '16' then (Sud.FileDescription + ' 2016')
            when '15' then (Sud.FileDescription + ' 2013')
            when '14' then (Sud.FileDescription + ' 2010')
        end) as Product,
       sud.FileVersion,
       sud.StartTimeLocal as LastExecuted
from v_R_system sy cross apply
     (select top (1) sud.*
      from v_GS_SoftwareUsageData sud 
      where sy.ResourceID = sud.ResourceID and
            sud.FileName = @ProductName + '.EXE' and
            sud.StartNotCaptured <> 1
      order by sud.StartTimeLocal desc, sud.FileName
     ) sud;

Upvotes: 1

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