Hi,
Remove the if statement. Just declare a boolean before the while and set it to
false. Inside the while statement, just set it to true. To check if empty set,
check the value of the boolean after the while. If it is true, then it is not
empty else its empty. It does not do any overheads or any performance
degradation. Thank
Regards
Mihir
sunil_s23 wrote:
> If we consider a large application; this involves
> doubling the number of SQL queries; one extra query
> for each query just to find out the count; I feel that
> we should be considering the overheads in accessing a
> database and executing a query and that too if it is
> over a network with heavy traffic.....
>
> --- King Maurice <[EMAIL PROTECTED]> wrote:
> > Economical way, your right its kinda tedious, but it
> > only about 4 simple
> > lines of code, how economical can you get, just pure
> > laziness maybe, but
> > that is up to your discretion, as long as you get
> > the job done.
> >
> >
> >
> > ----- Original Message -----
> > From: "sunil_s23" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Sent: Monday, June 18, 2001 12:07 PM
> > Subject: Re: Checking for Empty Result Set
> >
> >
> > > That calls for two sql statements; is there a more
> > > economical way out ?.
> > > The following code seems to work, but not always.
> > > Any pointers ?
> > >
> > > ResultSet rs = ps.executeQuery();
> > > if(rs.isBeforeFirst() == false)
> > > {
> > > System.out.println("empty result set");
> > > }
> > > else
> > > {
> > > while(rs.next())
> > > {
> > >
> > > System.out.println(rs.getString("EMPLOYEE_NAME"));
> > > }
> > > }
> > >
> > > --- King Maurice <[EMAIL PROTECTED]> wrote:
> > > > Well the get the count of the resultset in your
> > sql
> > > > command and then test
> > > > for a condition of one
> > > >
> > > > You need to figure out on your own, the
> > conditions
> > > > in your code, if not your
> > > > lost!!!!
> > > >
> > > > Maurice~
> > > >
> > > > ----- Original Message -----
> > > > From: "sunil_s23" <[EMAIL PROTECTED]>
> > > > To: <[EMAIL PROTECTED]>
> > > > Sent: Monday, June 18, 2001 11:58 AM
> > > > Subject: Re: Checking for Empty Result Set
> > > >
> > > >
> > > > > This definitely caters to the case when there
> > is
> > > > only
> > > > > one row in the result set; but what about the
> > case
> > > > if
> > > > > the result set contains more than one row. I
> > am
> > > > > looking for a solution which will handle both
> > > > single
> > > > > row results and multiple row results as well
> > as
> > > > the
> > > > > case when the result set is empty.
> > > > > Any suggestions ?,
> > > > > Thanks,
> > > > > Sunil.
> > > > >
> > > > > --- King Maurice <[EMAIL PROTECTED]>
> > wrote:
> > > > > > I see your problem
> > > > > >
> > > > > > Do this example or follow this example if
> > you
> > > > can
> > > > > > comprehend.
> > > > > >
> > > > > > Example below::
> > > > > >
> > > > > > if (! rs.next())
> > > > > > {
> > > > > > %>
> > > > > > <table><tr><td>empty result
> > > > set</td></tr></table>
> > > > > > <%
> > > > > > }
> > > > > > else
> > > > > > {
> > > > > > String employee =
> > > > rs.getString("EMPLOYEE_NAME"));
> > > > > > %>
> > > > > > <table><tr><td><%= employee
> > > > %></td></tr></table>
> > > > > > <%
> > > > > > }
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > > ----- Original Message -----
> > > > > > From: "sunil_s23" <[EMAIL PROTECTED]>
> > > > > > To: <[EMAIL PROTECTED]>
> > > > > > Sent: Monday, June 18, 2001 11:44 AM
> > > > > > Subject: Re: Checking for Empty Result Set
> > > > > >
> > > > > >
> > > > > > > See the code below, it does not work if
> > there
> > > > is a
> > > > > > > single row in the result set; in other
> > words
> > > > the
> > > > > > > statement if(!rs.next()) causes a row of
> > > > result
> > > > > > set to
> > > > > > > be skipped.
> > > > > > > Any suggestions ?,
> > > > > > > Sunil.
> > > > > > >
> > > > > > > ResultSet rs = ps.executeQuery();
> > > > > > > if(!rs.next())
> > > > > > > System.out.println("empty
> > result
> > > > > > set");
> > > > > > > while(rs.next())
> > > > > > > {
> > > > > > >
> > System.out.println(rs.getString
> > > > > > > ("EMPLOYEE_NAME"));
> > > > > > > }
> > > > > > >
> > > > > > > --- Satyanarayan Divakar
> > > > > > > <[EMAIL PROTECTED]> wrote:
> > > > > > > > if(!resultSet.next())
> > > > > > > > display"No Records Retreived";
> > > > > > > >
> > > > > > > > -----Original Message-----
> > > > > > > > From: sunil_s23
> > [mailto:[EMAIL PROTECTED]]
> > > > > > > > Sent: Monday, June 18, 2001 10:27 AM
> > > > > > > > To: [EMAIL PROTECTED]
> > > > > > > > Subject: Re: Checking for Empty Result
> > Set
> > > > > > > >
> > > > > > > >
> > > > > > > > Hi All,
> > > > > > > > A ResultSet is never null once we
> > execute a
> > > > > > > > PreparedStatement and assign the result
> > to
> > > > the
> > > > > > > > Result
> > > > > > > > Set.
> > > > > > > > Is there any other way of checking
> > whether a
> > > > > > > > ResultSet
> > > > > > > > is empty ?
> > > > > > > > Thanks,
> > > > > > > > Sunil.
> > > > > > > > --- King Maurice
> > <[EMAIL PROTECTED]>
> > > > > > wrote:
> > > > > > > > > IF RESULTSET IS EQUAL TO NULL
> > > > > > > > > DO SOMETHING,
> > > > > > > > > SUGGESTION:: NO RECORDS FOUND PLEASE
> > TRY
> > > > AGAIN
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > ----- Original Message -----
> > > > > > > > > From: "sunil_s23"
> > <[EMAIL PROTECTED]>
> > > > > > > > > To: <[EMAIL PROTECTED]>
> > > > > > > > > Sent: Monday, June 18, 2001 11:00 AM
> > > > > > > > > Subject: Checking for Empty Result Set
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > > Hello,
> > > > > > > > > > Which is the best method for
> > checking
> > > > > > whether a
> > > > > > > > > Result
> > > > > > > > > > Set is empty ?
> > > > > > > > > >
> > > > > > > > > > ResultSet rs =
> > prestmt.exeucteUpdate();
> > > > > > > > > > Checking for rs.isBeforeFirst()
> > > > returning
> > > > > > false
> > > > > > > > > does
> > > > > > > > > > not seem to work always....
> > > > > > > > > > Thanks in advance,
> > > > > > > > > > Sunil.
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> >
> === message truncated ===
>
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