Re: Entering '<1' and 'BDL'

On Tue, 20 Apr 2010, Ewan, Michael wrote:

> As you noted, NULL will fit the bill for your NAN values, but make sure
> the table allows NULL's in that column and that your code handles NULL's
> either by skipping them (a self join can often help) or by converting them
> to 0 if you want them to count in the statistics.

Michael,

There are always valid reasons for missing data: stream channel is dry or
water is frozen; mill not operating; lab equipment malfunction. While
regulators might be interested in how many values are missing, they tend to
be more interested in values that exceed statutory thresholds. Regardless,
we will be able to provide them with the information they want.

Thanks,

Rich