"Martijn Tonies" <[EMAIL PROTECTED]> wrote on 16/03/2006 11:02:32:
> Well, the question still is if you should store "unknown" at all ;) > > Not according to Date: you should store what is known. See the remarks > about the "true propositions", from which relational databases are derived > (but you probably know that). As someone totally unread in the theory of databases, that seems unduly puritanical. I assume that what Date would propose is that you have another table (related by master key) in which, if you do not know something, you do not enter it. But this means that if you have 10 different pieces of potentially but not necessarily available information about a single master record (e.g. a person), you have to do a 10-way join in order to retrieve all the information about them. Replacing a theoretically ugly null flag with a 10 way join strikes me, as an engineer rather than a theoretician, the wrong side of the elegance/practicality trade-off. Alec -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
