问题
Oracle provides functions to test whether a stored value is NaN or +-infinity. Is there something similar that can be used in Access and Sql Server?
回答1:
Yes, Access can detect "NaN" and "+/-Infinity", at least for values that reside in Double columns of a native Access table:
You can even have Access perform queries like the following, which will return all rows that contain a "NaN" (positive or negative) in the Double column:
SELECT * FROM Table1 WHERE Right(CStr([DoubleField]), 3) = 'NAN';
However, support for those special values could very well be incomplete. For example, I'm not aware of a way to insert or update those values (e.g., CDbl("1.#INF") does not work.)
来源：https://stackoverflow.com/questions/33192022/detecting-not-a-number-nan-or-infinity-in-access-and-sql-server