>From what I understand, the first query is only slightly faster than the
second (since it doesn't have to build a full ResultSet), but Oracle has
pretty aggressive caching, so the second query (having the same where
clause) should run out of the cached data from the first call and be very
quick. Overall, it's slower, but nowhere near twice as slow.
(*Chris*)
----- Original Message -----
From: Xizhen Wang <[EMAIL PROTECTED]>
To: Chris Pratt <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Cc: <[EMAIL PROTECTED]>
Sent: Monday, June 28, 1999 6:34 PM
Subject: Re: Number of rows a query retrieved?
>
>
> Chris Pratt wrote:
> >
> > Oh, I should have mentioned, that using simple SQL, you can also use the
> > COUNT operator to test how many rows will be returned. Like this:
> >
> > select count(*) from employees where city='San Jose'
> > select * from employees where city='San Jose'
>
> Thank you!
> So another question is: is the first query as time-comsuming as the 2nd
> one?
> if this is true, i'd rather do only one query.
>
> thanks!
>
> xizhen
>
>
> >
> > The first query will return a single row in its ResultSet that consists
of
> > one Numeric value equal to the number of rows that the second query will
> > return (Assuming that no updates happen between the two invocations).
> > (*Chris*)
> >
> > ----- Original Message -----
> > From: Chris Pratt <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
> > Sent: Monday, June 28, 1999 2:42 PM
> > Subject: Re: Number of rows a query retrieved?
> >
> > > In standard JDBC, there is no way to tell this before you have read
the
> > last
> > > row. There are packages, like Village or Town, that do have this
> > > capability, but I have not tested them. You could also use a true
OODB,
> > > like CloudScape, which has this type of capability.
> > > (*Chris*)
> > >
> > > ----- Original Message -----
> > > From: Xizhen Wang <[EMAIL PROTECTED]>
> > > To: <[EMAIL PROTECTED]>
> > > Sent: Monday, June 28, 1999 12:44 AM
> > > Subject: Number of rows a query retrieved?
> > >
> > >
> > > > Hi! In jdbc, how to know the number of rows a query retrieved? Is
there
> > > > a good way other than using ResultSet.next()?
> > > >
> > > > Thanks!
> > > >
> > > >
> > >
> >
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>
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