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From: Richard Broersma Jr <[email protected]>
To: [email protected]
Subject: Valued Predicates
Date: Wed, 15 Nov 2006 21:55:21 -0800 (PST)
Message-ID: <[email protected]> (raw)

In my reading of SQL for smarties I've stumbled across syntax that is supported by Postgresql. 
However, I can't find mention of it in the Postgresql Docs.  Would an appropriate location for
this syntax be the "where condition" of the insert/update/select/delete statements?

i.e.

mydb=# select * from test2 where ( (a,b) >= (1,'A') ) is unknown;
 a | b
---+---
 3 |
(1 row)
mydb=# select * from test2 where ( (a,b) >= (1,'A') ) is true;
 a |   b
---+--------
 1 | Albert
 2 | Bert
(2 rows)
mydb=# select * from test2 where ( (a,b) >= (1,'A') ) is false;
 a | b
---+---
(0 rows)
mydb=# select * from test2 where ( (a,b) >= (1,'A') ) is not false;
 a |   b
---+--------
 1 | Albert
 2 | Bert
 3 |
(3 rows)
mydb=# select * from test2 where ( (a,b) >= (1,'A') ) is not true;
 a | b
---+---
 3 |
(1 row)
mydb=# select * from test2 where ( (a,b) >= (1,'A') ) is not true;
 a | b
---+---
 3 |
(1 row)

Regards,

Richard Broersma Jr.

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