re:Data modeling issues for a travel planning system
From: hensome2004 <henrychang04_at_hotmail-dot-com.no-spam.invalid>
Date: Sat, 05 Nov 2005 02:10:29 -0600
Message-ID: <s6idnTIAUJ9o9fHeRVn_vA_at_giganews.com>
Date: Sat, 05 Nov 2005 02:10:29 -0600
Message-ID: <s6idnTIAUJ9o9fHeRVn_vA_at_giganews.com>
Thanks Kevin.
But looking into the STATION_LINE table, it is not normalised if we use one PK. The primary key of this table should be a composite key, made up of 3 columns, line_id, stat_id, and direction_id. This is because the next station is only determined by these 3 attributes together.
In addition, do I miss something in the tables if you consider the requirements carefully?
Anyone has suggestion on this? Thanks a lot!!
- Henry