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Date: Thu, 08 Nov 2007 10:18:46 -0800
From: Stanley Bradbury <Stan.Bradbury@gmail.com>
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To: Derby Discussion <derby-user@db.apache.org>
Subject: Re: Quering on multiple rows
References: <13651100.post@talk.nabble.com> <47334B6B.3010000@gmail.com>
 <13652328.post@talk.nabble.com>
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I was confused by you use of 'constraint' - I was thinking of data 
integrity constraints implemented by foreign keys or UNIQUE or NOT 
NULL.  I think Kristian pointed you in the right direction, use one of 
the basic or qualified predicates to retrieve the records you wish.

Patrick Sp. wrote:
> Hi Stanley,
>
> Thank you for your response.
> This is what is actually done. My question is rather about the SQL statement
> I need to execute in order to be  able to express constraints on multiple
> rows on the Mission table related to one specific employee.
> Any help is appreciated.
> Thanks
> P. 
>
> ---   
> In many ways this is a matter of preference but, IMHO, since both 
> Missions and Employee seem to be primary objects and there could be a 
> M:M relationship I would create an association table with two columns 
> Mission_id and    Employee_id and, for good form, throw in a 
> auto-increment column to be used as the primary key of the table (or the 
> compound key Mission_id and Employee_id could be used as the PK).
>
>  
>
>