StDev, StDevP Functions (SQL Only)
See Also Example >Low
Return estimates of the standard deviation for a population or a population sample represented as a set of values contained in a specified field on a query.
StDev( expr )
StDevP( expr )
StDevP evaluates a population, and StDev evaluates a population sample.
The StDev and StDevP functions use the following argument.
expr String expression identifying the field that contains the numeric data you want to evaluate, or an expression that performs a calculation using the data in that field. Operands in expr can include the name of a table field, or a Visual Basic function (which can be intrinsic but not a user-defined function or one of the other domain aggregate or SQL aggregate functions).
If the underlying query contains fewer than two records (or no records, for StDevP), these functions return a Null (which indicates that a standard deviation can't be calculated).