Re: 3 value logic. Why is SQL so special?

From: David Portas <REMOVE_BEFORE_REPLYING_dportas_at_acm.org>
Date: 16 Sep 2006 10:56:59 -0700
Message-ID: <1158429419.750867.38460_at_m7g2000cwm.googlegroups.com>


Cimode wrote:
> A UNION equivalent an LEFT OUTER JOIN BULLSHIT!!!. A LEFT OUTER JOIN is
> just SQL miserable way to force a presentation inspired perspective
> into design issues that should be regulated by normalization to
> preserve integrity. The proof is that you can do a UNION using 2
> relations but using LEFT OUTER JOIN when dealing with relations has no
> meaning. Consider 2 tables table1(id1, key1) and table2(id2, key2)
>
> Table1
> 1, A
> 2, B
> 3, C
>
> Table2
> 8, A
> 10, C
>

T1{k,i1,i2} UNION (T1{k,i1} JOIN T2{k,i2})

Obviously some suitable value or expression has to be supplied for i2 on the left hand side of the UNION.

-- 
David Portas
Received on Sat Sep 16 2006 - 19:56:59 CEST

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