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From: Lennart Jonsson <erik.lennart.jonsson@gmail.com>
Newsgroups: comp.databases.ms-sqlserver
Subject: Re: Sql question
Date: Mon, 02 Feb 2015 08:45:09 +0100
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On 2015-02-02 07:16, rja.carnegie@gmail.com wrote:
[...]
> I wonder if you need to write the statement as a JOIN
> given that we know we're interested in "wives" of
> employee id = 3.  Why not just:
>
> SELECT * FROM Employee WHERE EmpPartner = 3;
>

Yes, good observation


> This is a strange problem in many ways.  One database
> seems to contain multiple firms and their employees,
> and the tax authorities get to use it as well?
> And it's implied that any possible wife is recorded
> in the employee table?
>

Agreed


[...]

>
> Enforcement would meant that only one Employee -
> one wife - can have EmpPartner = 3.
>
> I'm not sure how to write that rule.
>

UNIQUE ( EmpPartner );


> Anyway, maybe the database designer anticipated
> legal polygamy if Mitt Romney had won.
>

:-)

[...]