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Why should we set the primary key as not null

 
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imain
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Joined: 25 Jun 2006
Posts: 14
Location: US

PostPosted: Wed Aug 09, 2006 10:24 am    Post subject: Why should we set the primary key as not null
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HI All

Can anyone tell me the difference between setting the primary key and creating an index?
Why should we set the primary key as not null?
What difference is there in an index when the index is created as UNIQUE?

THanks in advance
imain
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Jerry

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Joined: 16 Sep 2005
Posts: 42

PostPosted: Fri Aug 18, 2006 5:52 pm    Post subject:
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Hi imain,

I guess this link would help you, in case you had not gone through it before:

http://www.ibmmainframes.com/viewtopic.php?t=10227&highlight=primary+key[url][/url]
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