Groups > comp.lang.java.programmer > #2750

Re: ORM or JDBC?

From	Lew <noone@lewscanon.com>
Newsgroups	comp.lang.java.programmer
Subject	Re: ORM or JDBC?
Date	2011-04-02 10:25 -0400
Organization	albasani.net
Message-ID	<in7bjt$p0n$1@news.albasani.net> (permalink)
References	(11 earlier) <IX7lp.805$YL5.263@newsfe05.iad> <alpine.DEB.2.00.1104012238090.16545@urchin.earth.li> <LQslp.6717$sS4.1488@newsfe11.iad> <in62hr$odq$6@lust.ihug.co.nz> <QKElp.4837$0s5.485@newsfe17.iad>

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Arved Sandstrom wrote:
> There is no super-distinct boundary, no. But there is a boundary
> nonetheless. In the conceptual (semantic) model when we are thinking
> about Person, we'll have a notion of Person identity - what attributes
> of Person make them unique - but at this level that uniqueness could be
> opaquely described as PersonID of no particular datatype, and we then go
> on to discuss other attributes of Person that are necessary for the
> business problem. Similarly, when thinking at this conceptual level
> about LifeEvent, we might simply say that each LifeEvent instance will
> point at a Person using the PersonId value.

To this excellent taxonomy I would add only that the conceptual "PersonID" 
would identify the natural, or innate identifying data, one might say the 
"primary key".  That's not correct at this level, though - what we're aiming 
for are the attributes that determine entity identity within the semantic model.

A surrogate key, such as an integer-valued ID that perhaps is from a sequence, 
is something introduced in the physical model.

-- 
Lew

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Re: ORM or JDBC? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-03-31 13:19 +1300
  Re: ORM or JDBC? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-03-31 20:16 -0300
    Re: ORM or JDBC? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-04-01 13:10 +1300
      Re: ORM or JDBC? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-04-01 20:12 -0300
        Re: ORM or JDBC? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-04-02 15:45 +1300
          Re: ORM or JDBC? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-04-02 09:21 -0300
    Re: ORM or JDBC? Tom Anderson <twic@urchin.earth.li> - 2011-04-01 22:38 +0100
      Re: ORM or JDBC? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-04-01 20:03 -0300
        Re: ORM or JDBC? Lawrence D'Oliveiro <ldo@geek-central.gen.new_zealand> - 2011-04-02 15:44 +1300
          Re: ORM or JDBC? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-04-02 09:35 -0300
            Re: ORM or JDBC? Lew <noone@lewscanon.com> - 2011-04-02 10:25 -0400

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