I'm setting up a database to track calibration of laboratory pipettes. Calibration requires taking five replicate weights of water per pipette and calculating average and Standard deviation. I'm ok with calculating the average in a query...however the problem is calculating Standard Deviation! I've tried using StDEV in "tools" with no luck! I believe the problem is how I'm setting up these five replicates? A co-worker suggested making each replicate a separate query and then using a Union query. Any help will be appreciated. Thanks in advance!
If you are graphing the data then a Union query would be okay. A union query has to be done in SQL;
example Select Field1, Field2 From tablename
Select Field1, Field2 from anothertableName
Note that the union requires the same number of fields and datatypes in order.
However if you are trying to rejoin all the calcs to the proper pipettes in a single row, then what you need is to do several queries that do each calc along with that pipettes' identifier in the result set. Then do another query that rejoins the results to each other on the identifier field to get all results for that pipette in a single row.