-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 02/23/07 15:47, Peter Eisentraut wrote: > Brandon Aiken wrote: >> That's why you make a table for every device or every measurement, >> and then use a view to consolidate it. With updatable views, there's >> no excuse not to. > > No, you put them all on one table and put nulls in places where no data > is available. With real database systems, there's no excuse not to. Each of the daily/hourly/etc temperature readings are independent. Therefore they should each have their own row in the "meteorology readings" table. I *think* that breaks 3NF. This "should" be 3NF: CREATE TABLE T_READING_TYPE ( READING_CODE CHAR(4) PRIMARY KEY, READING_DESCRIP TEXT ); CREATE TABLE T_MET_READINGS ( _DATE DATE, _HOUR SMALLINT CHECK (HOUR BETWEEN 0 AND 23), READING_CODE CHAR(4) REFERENCES T_READING_TYPE(READING_CODE), READING_VALUE NUMERIC(8,3), PRIMARY KEY (_DATE, _HOUR) ); -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFF32j3S9HxQb37XmcRAgsgAKC7m74VtyU5rnOI0gF2VXjHxk9kXgCfVY86 i5hgysDkC7EUJWlbGL+vyZM= =RN+L -----END PGP SIGNATURE-----
