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How to retrieve first row in a table in efficient way ?

 
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aryanpa1

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Joined: 26 May 2007
Posts: 45
Location: Chennai

PostPosted: Thu Jul 05, 2007 8:49 pm    Post subject: How to retrieve first row in a table in efficient way ?
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Hi ,

Can any body suggest me to retrieve the first row from a table in efficient way.

Thanks,
pavan
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dick scherrer

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Joined: 23 Nov 2006
Posts: 19270
Location: Inside the Matrix

PostPosted: Thu Jul 05, 2007 9:37 pm    Post subject:
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Hello,

What is meant by "first row"?

Sequential files have a first and last record, but databases do not have the same.

Keep in mind that most database processing is done via one or more keys. There is no "first".
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Anuj Dhawan

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Joined: 22 Apr 2006
Posts: 6258
Location: Mumbai, India

PostPosted: Thu Jul 05, 2007 9:42 pm    Post subject:
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Pavan,

This can be one way:

Code:
SELECT * FROM table Name
FETCH FIRST ROW ONLY       
WITH UR;                   
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dick scherrer

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Joined: 23 Nov 2006
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PostPosted: Thu Jul 05, 2007 10:09 pm    Post subject:
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Hello,

That will fetch one record - not sure i understand how that would be "the first row from a table" icon_confused.gif . It would be the first row that particular query fetches, but that does not imply the first row in the table.

As i mentioned earlier, until what "first row" really means is defined, there is no way to read it and besides, there is not a "first row in the table" concept in most database systems.
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aryanpa1

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Joined: 26 May 2007
Posts: 45
Location: Chennai

PostPosted: Thu Jul 05, 2007 11:19 pm    Post subject:
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Hi Anuj ,

It worked. Thankyou...
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stodolas

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Joined: 13 Jun 2007
Posts: 632
Location: Wisconsin

PostPosted: Fri Jul 06, 2007 6:00 am    Post subject:
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Code:

SELECT * FROM table Name
FETCH FIRST ROW ONLY       
WITH UR;   


Is extremely useless. You just arbitrarily selected a row. It could be different the next time you do it, or it could be the same for the life of the table.

This is a complete waste of a query without a ORDER BY clause.
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