Calculating Average over date - sql

Question

I try to calculate an average of value over time: I created a tablix in ssrs:
I used this expression in my query:
Avg(case when CounterName = 'Count 1' then calculationUnits end) as Average
The Average which is shown in the picture:
=SUM(Fields!Prod.Value)/3
I divided the Sum of the Values by 3 (in a day there are 3 shifts) but I would like to have an average over the date.
Can I use in my query something with:
OVER(PARTITION BY [intervaldate])
I would like to divide the sum of each machines by the numbers of date value

Answer 1

Try getting just the rows for each date in your dateset and use the SSRS functions to get the average and the sum.
To filter you query in SQL use the the parameters inside the SQL Statement.
Your query should look something like this:
select
*
from
yourData
where
date BETWEEN #StartDate AND #EndDate
Example data for this statement:
yourDate M101 M102 M103
2015-12-24 12:00:00 100 34 54
2015-12-25 12:00:00 25 67 87
2015-12-26 12:00:00 30 434 54
2015-12-27 12:00:00 140 42 65
2015-12-28 12:00:00 21 66 77
Now create a tablix containing the data in your SSRS report. Add two new rows outside of your detail group:
Now add expressions in the new rows, to get the sum and the average, example for M101:
for sum:
=Sum(Fields!M101.Value)
for average (over date)
=SUM(Fields!Prod.Value) / COUNTDISTINCT(Fields!DateValue.Value)

Answer 2

I don't really see the relationship between your snippet of code and the example data. However, the logic that you want is probably:
Avg(case when CounterName = 'Count 1' then calculationUnits end) as Average
Note that there is no else clause. Without the else the case expression evaluates to NULL, which is ignored by avg().
Your expression has else 0. This is treated as a legitimate value, so non-matching rows affect the final results.