Hi Kate,

You should be able to get the results you’re looking for with a relatively simple multi-step filter process.

This will utilise several filters across the ‘ChemQA1_Chemistry_Samples’ and ‘ChemQA2_Chemistry_Samples_with_Raw_Results’ views.

I will use the sample database provided with ESdat for these examples.

Filter to the specific date ranges you are interested in.  There may be several ways you can do this depending on the data you have populated (Monitoring_Round, Sample_Date-Time). 

In the ‘ChemQA2_Chemistry_Samples_with_Raw_Results’ view, I am going to filter by a date range using the filter:

[Sampled_Date-Time] Between #01 Jan 2010# And #31 Jan 2010#

(You can also include other filters such as Sample_Type and Matrix_Type, to filter to the exact samples you require.)

Applying this filter will list all the results for your required date range (detects or not).

I then append ‘AND Prefix Is Null’ to the filter, which will show all the results that have detects (which is actually the inverse of what you’re looking for).  So, my filter is now:

[Sampled_Date-Time] Between #01 Jan 2010# And #31 Jan 2010# AND Prefix is Null

Switch to the filter view and check “within applied filter only”.  Select ‘SampleCode’ from the list of Fields on the left, and then press “All to Filter”.

Switch to the ‘ChemQA1_Chemistry_Samples’ view, and edit the filter to remove the ‘AND Prefix Is Null’ section.  This will list all the samples for your date range that have results (again the inverse of what you want).

One final edit to the filter will get what you’re looking for. 

Edit the filter between ‘SampleCode’ and ‘In’, type in the word ‘Not’ and click “Apply Filter”. 

You will now have a list of all the samples in that date range that do not have any concentrations above the detection limit, which is what you are after.

Thanks,

Nick