Re: A simple notation, again

From: Lennart <>
Date: Wed, 18 Jul 2007 21:52:32 +0200
Message-ID: <f7lr20$t4v$>

Brian Selzer wrote:

>> You imply order (adjacency) when relation attributes should not be
>> subjected to any....

> True, but order is imposed here simply to associate each element of each
> tuple with its designation. It is used only as a shorthand.

I've been playing with Dee ( on and off for a while and there it is possible to do it /both/ ways:

To assign a relation value to a relation variable, use the standard Python syntax, e.g.

 >>> IS_CALLED = Relation(["StudentId", "Name"],

...                     [{"StudentId":'S1', "Name":'Anne'},
...                      {"StudentId":'S2', "Name":'Boris'},
...                      {"StudentId":'S3', "Name":'Cindy'},
...                      {"StudentId":'S4', "Name":'Devinder'},
...                      {"StudentId":'S5', "Name":'Boris'},
...                     ])


or alteratively, a more concise option is available which relies on the order of the body attributes matching the order of the heading:

 >>> IS_CALLED = Relation(["StudentId", "Name"],
...                     [('S1', 'Anne'),
...                      ('S2', 'Boris'),
...                      ('S3', 'Cindy'),
...                      ('S4', 'Devinder'),
...                      ('S5', 'Boris'),
...                     ])

Since I'm a lousy typist I tend to use the latter ;-)

/Lennart Received on Wed Jul 18 2007 - 21:52:32 CEST

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