Unknown measurement values (NULL for SQL)
Question
After setting up the weather station and having been struck by the schema errors (decimal definitions) and a connectivity error (mysql2300 does not yet deal with this) I'd say that it would be nice to have a concept of "bad measurement". Allowing NULL values in the SQL table schema (excluding datetime) would add knowledge of the specific value being not known instead of it being forced be a value of some sort (or to skip the row entirely). NULL values are anyway acceptable in e.g. chart -drawing libraries (at least the ones I've tested :)).
Funny that after a nights sleep, some ideas don't seems as good they were... :). Come to think of it, if NULL values are allowed, apps would probably have to check for them every time, hmm... :/. Oh well, if we would put indoor measurements in one table and outdoor measurements into another, skipping a row in the outdoor table would not hurt the indoor measurements. Then again, I think the connectivity errors are sparse enough so that this table splitting would not be needed....
Environment
Open2300 version: |
1.11 |
Libraries: |
mysql |
Server OS: |
Debian GNU/Linux (2.6.21.1 unstable) |
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KimmoKoskinen - 05 Aug 2007
Answer