When running an Analytical Results Report where SAMPLE_DATE is set to a specified date range, results with SAMPLE_DATE = (none) will be returned if the user data includes samples where the SAMPLE_DATE = null.
NULL means that the date is unknown, and this is why the report(s) include samples with SAMPLE_DATE is Null. Since the date is unknown, it is possible (though unknown) that the SAMPLE_DATE value (if known) would be within the requested range. Since the SAMPLE_DATE is null, the query cannot guarantee that SAMPLE_DATE is not within the specified range (nor can it guarantee that the SAMPLE_DATE is within the specified range).
When the Analytical Results Report was created, it was necessary to decide whether to always exclude samples with Null SAMPLE_DATE or to always include them. The risk of both options was considered, including samples that map but may not really belong in the output or excluding samples that may actually belong in the output. EQuIS is intended to improve data management, and the decision was made to include these unknown samples and let the Data Manager determine whether these samples required a SAMPLE_DATE or not.
Copyright © 2021 EarthSoft, Inc • Modified: 02 Apr 2020