Re: Number of rows in a ResultSet ?

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От Michael Stephenson
Тема Re: Number of rows in a ResultSet ?
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Msg-id Pine.LNX.4.30.0101181434130.2688-100000@tirin.openworld.co.uk
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Ответ на Number of rows in a ResultSet ?  (Thierry Dart <dart@u444.jussieu.fr>)
Ответы Re: Number of rows in a ResultSet ?  (Peter T Mount <peter@retep.org.uk>)
Список pgsql-interfaces
> I need to know how many rows exist in a ResultSet. I've tried to use
> getFetchSize() method of ResultSet interface, but a message was
> displayed "this method is not yet implemented".
>
> Anyone can help me ?

You could use: ResultSet.last(); int numberOfRows = ResultSet.getRow();

Now, my understanding of this area is a but sketchy, but I think that
most implementations of ResultSet do not get all of the results in one go
(like the PostgreSQL JDBC driver does), so getFetchSize() is not a safe
way of determining the number of results returned.

Or, you could do another query with count() in your sql..

Or (and I wouldn't do this without carefully looking at the jdbc spec),
you could just alter the getFetchSize() method
org.postgresql.jdbc2.ResultSet driver to look like:
   public int getFetchSize() throws SQLException   {return rows.size();   }

The choice is yours..

Michael Stephenson      mstephenson@openworld.co.uk
Developer   -    Web Applications    -   Open World
Tel: +44 1225 444 950         Fax: +44 1225 336 738



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