On Thursday, May 24, 2018, Ron <ronljohnso...@gmail.com> wrote: > On 05/24/2018 10:15 AM, Martin Mueller wrote: > >> You construct a z-score for a set of values by subtracting the average >> from the value and dividing the result by the standard deviation. I know >> how to do this in a two-step procedure. First, I compute the average and >> standard deviation. In a second run I use the formula and apply it to each >> value. >> >> Is there a way of doing this in a single-step procedure or can you chain >> the two parts together in one query? This goes beyond my SQL competence. >> > > What about this? > > SELECT value, (value - AVG(value))/stddev(value) as zvalue > FROM sometable > WHERE some conditions > GROUP by value >
That is syntactically correct but doesn't provide the correct answer. David J.
