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From Rainer Döbele <doeb...@esteam.de>
Subject re: How to tell that a rows is UNIQUE ?
Date Wed, 18 May 2011 20:36:44 GMT
Hi exxos,

yes, looks like somebody else's answer was faster and better.

Possibly this is a sign that I am becoming old ;-)

Great to hear that you found what you were looking for.

Rainer


> from: exxos [mailto:hatufr@gmail.com] 
> to: empire-db-user@incubator.apache.org
> re: Re: How to tell that a rows is UNIQUE ?
>
> Hej Rainer,
>
> I noticed this, but here it was about defining a column in a table that is not allowed
to contain the same value twice. The index seems dedicated for that issue.
>
> Regards,
> exxos.
>
> On Wed, May 18, 2011 at 9:26 PM, Rainer Döbele <doebele@esteam.de> wrote:
> Hi exxos,
>
> I don't quite understand your question.
> What do you consider a unique column?
>
> Some databases allow integer columns that are automatically populated from a sequence
(e.g. identity columns in Microsoft SQL).
>
> Another feature in Microsoft sql is the data type "uniqueidentifier" which is a guid
that will be automatically generated for each row.
>
> For those two cases Empire-db offers the data types DataType.AUTOINC and DataType.UNIQUEID.
> The exact implementation however is database specific. The Oracle driver e.g. will create
a number column and >automatically create a sequence for AutoInc columns (on DDL generation).
>
> Does this answer help you?
>
> Regards
> Rainer
>
>
> Exxos wrote:
> > from: exxos [mailto:hatufr@gmail.com]
> > to: empire-db-user@incubator.apache.org
> > re: How to tell that a rows is UNIQUE ?
> >
> > Hello,
> >
> > At the colomn declartion in DBTable, how to tell that a colomn is unique ?
> > (I'm not talking about primaries keys)
> >
> > Regards,
> > exxos.


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