Groups > comp.lang.java.databases > #140

Re: hibernate: mapping he

From	"Lew" <lew@THRWHITE.remove-dii-this>
Subject	Re: hibernate: mapping he
Message-ID	<9uydnUYir8zqa6rVnZ2dnUVZ_sGdnZ2d@comcast.com> (permalink)
Newsgroups	comp.lang.java.databases
References	<g18o8b$s52$1@nnrp.ngi.it>
Date	2011-04-27 15:21 +0000
Organization	TDS.net

Show all headers | View raw

  To: comp.lang.java.databases
Matteo wrote:
> A composite key can be translated to a surrogate key quite easily:
> (fieldA, fieldB) primary key NOT NULL
> is equal to
> surrogateKey PRIMARY KEY NOT NULL
> (fieldA, fieldB) UNIQUE NOT NULL
> 
> This will save you from a lot of headhaches with Hibernate.

Unfortunately this causes headaches in the data model.  Entity tables can 
sport such surrogate keys, but linking tables, where "fieldA" and "fieldB" are 
both keys into other tables, get pretty fubared when you throw a superfluous 
surrogate key onto the them.  The extra key gets in the way of JOINs.

-- 
Lew

---
 * Synchronet * The Whitehouse BBS --- whitehouse.hulds.com --- check it out free usenet!
--- Synchronet 3.15a-Win32 NewsLink 1.92
Time Warp of the Future BBS - telnet://time.synchro.net:24

Back to comp.lang.java.databases | Previous | Next — Previous in thread | Find similar

Thread

hibernate: mapping help "Matteo" <matteo@THRWHITE.remove-dii-this> - 2011-04-27 15:21 +0000
  Re: hibernate: mapping he "Lew" <lew@THRWHITE.remove-dii-this> - 2011-04-27 15:21 +0000
    Re: hibernate: mapping he "Matteo" <matteo@THRWHITE.remove-dii-this> - 2011-04-27 15:21 +0000
      Re: hibernate: mapping he "Lew" <lew@THRWHITE.remove-dii-this> - 2011-04-27 15:21 +0000
        Re: hibernate: mapping he "Matteo" <matteo@THRWHITE.remove-dii-this> - 2011-04-27 15:21 +0000
          Re: hibernate: mapping he "Lew" <lew@THRWHITE.remove-dii-this> - 2011-04-27 15:21 +0000

csiph-web