I have 3 columns (DateTime, GroupName, Value), some of these groups are closely related and I would like to display these in a stacked graph. The problem I am facing (I THINK) is that I don't have entries for all groups at all times.
(cannot find a decent way to add a table, so here is some code)
Datetime  Groupname   Value
1         a   whatever
1         b   whatever
1         c   whatever
2         a   whatever
2         b   whatever
3         a   whatever
3         b   whatever
3         c   whatever
4         b   whateverSo in the example I don't have an entry for C at time 2. And I also don't have an entry for A and B at time 4.
Resulting in: edit: added to onedrive link
With my limited SQL skills I am not sure how to fix this. How do I get the graph to connect the points from the DateTime points where we do have data, and ignore DateTime points where we do not have data?
11-07-2016 Edit
Ok, so here some pictures of the actual data
No rep - Onedrive it is https://1drv.ms/f/s!AhKMFQBAmZ7GgYEMzdpTBvuXTi5gAQ
the graph looks different than my first example because I set the X-axis to scalar.
On 7/5/2016 and 7/6/2016 (month/day/year notation) the CH3 is low and 0. If I remove CH3 from results the graph looks ok.
@sqlandmore.com This is the query. Very basic. Data is coming from a database were the datetime is not in a proper datetime format so thats gets converted into the wimsview.
SELECT
 WimsView.TagID
 ,WimsView.SampleDateTime
 ,WimsView.SampleValue
 ,WimsView.TagName
FROM
  WimsView
WHERE
 WimsView.SampleDateTime > N'07/4/2016 00:00:00'
 AND ((WimsView.TagName LIKE N'%MBA%') OR (WimsView.TagName LIKE N'%MBB%')    OR (WimsView.TagName LIKE N'%GF1_DPC%')OR (WimsView.TagName LIKE N'%KF1_DPC%')OR    (WimsView.TagName LIKE N'%CH3_DPC%')) 
 AND WimsView.SampleValue IS NOT NULL
 
    