Strictly speaking, optional items are one-to-many associations. The semantic of an one-to-one association is 1:1 not 1:0,1. So I assume one-to-one's are not advised because it's better to put the data in one table to avoid the hassle with aligning id's and the join in each access.
-- Wolfgang From: [email protected] [mailto:[email protected]] On Behalf Of Tim Barcz Sent: Dienstag, 13. Januar 2009 18:06 To: [email protected] Subject: [nhusers] Re: Mapping one-to-one entities Can you explain why one to one is not advised? We use one-to-one in a non-legacy system, generally for items which are optional. The other way we could do this would be to represent the object as a many to many, which now structures the data in a way that is inconsistent with how we use the data. Again, why is one-to-one "not advised"? Tim On Tue, Jan 13, 2009 at 10:01 AM, Will Shaver <[email protected]> wrote: One-to-one is not advised for new database design, but is supplied for legacy databases. I am using one-to-one to map out the legacy databases that I have to deal with and it works fine. I recently fixed a bug so now one-to-one mapping with composite keys will work. -Will On Tue, Jan 13, 2009 at 2:20 AM, Adeel <[email protected]> wrote: Again, for my current project which involves a legacy database, I need to map entities who have a one-to-one relationship. This translates to the following: An entity "person", which is stored in a "person"- table, always has one and only one SearcProfile, which is another entity, stored in the "SearchProfile"-table. The Searchprofile also has a one-to-one relationship with the Person. As I understand, using One-To-One mappings is not advised. But what would be the fitting strategy for mapping such a relation... --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "nhusers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nhusers?hl=en -~----------~----~----~----~------~----~------~--~---
