On 6 Dec 2002 at 10:45, Jodi Kanter wrote: > I am creating a simple database that will hold information about > various pu= blications. There are keywords that are associated with > these publications = and there can be anywhere from 1 to about 6 of > these different keywords. > > As I see it I have two choices: > > 1) create keyword fields 1-6 in the publications database and accept > that s= ome of these fields will be empty.
That is unnormalized data and will make queries more awkward. > 2) create two tables: > "publication" and "keyword". In this scenario I have = no limit on the > amount of keywords that are used You can control the number of keywords in the application and via triggers in the database. > and I don't have empty fie= lds. What is the signifiance of empty fields? You can always determine the number of keywords for a given publication with this: select count(*) from keywords, pubication where keywords.publication_id = publication.id; > However, many of the keywords repeat for different publications. In > th= is situation I would have some repeating words in the columns. There's nothing wrong with that > I lean toward #2 but wanted to see if there was a preferred standard > or ano= ther possibility that I am overlooking?? I would recommend #2. -- Dan Langille : http://www.langille.org/ ---------------------------(end of broadcast)--------------------------- TIP 6: Have you searched our list archives? http://archives.postgresql.org
