I had exactly this problem a while ago, when I needed to check whether
a given ResultSet was empty, and if not, how many rows did it have. I'm
rather new to JDBC and SQL, but since I couldn't find any appropriate
methods, I wrote the following class (swedish comments removed :-) :
import java.sql.*;
public final class Utilities {
private Utilities() { }
public static boolean isEmpty(ResultSet rs) throws SQLException {
boolean result = !rs.next();
rs.beforeFirst();
return result;
}
public static int getRowCount(ResultSet rs) throws SQLException {
int i = 0;
while (rs.next()) i++;
rs.beforeFirst();
return i;
}
}
Then just use it like this:
if (Utilities.isEmpty(rs)) {
// empty
}
or, you could:
if (Utilities.getRowCount(rs) == 0) {
// empty
}
Hope this helps.
[ Matthias Carlsson ]
[ Programmer (Java, CGI/Perl, Javascript, HTML) ] [ Web Designer ]
[ E-Mail : [EMAIL PROTECTED] ] [ ICQ: 1430647 ]
> -----Ursprungligt meddelande-----
> Fr�n: A mailing list for discussion about Sun Microsystem's Java Servlet
> API Technology. [mailto:[EMAIL PROTECTED]]F�r James Lee
> Skickat: den 24 augusti 2000 18:28
> Till: [EMAIL PROTECTED]
> �mne: how to check ResultSet is null or not?
>
>
> Hi All,
>
> I want to display a message when the ResultSet is empty from the database.
> But when I try to check ResultSet by using the following methods like:
> if ( rset == null ) {
> // display the message
> } else {
> // display the results
> }
> it seems not working. I also tried to use
> if ( !rset.next() ) and if (!rset.first()) but none of them seems
> work.
>
> I am using Weblogic JDBC2.0 connection pool. It works fine if I do not
> check the ResultSet and just display them. Only thing is I got a
> blank page
> if no results.
>
> Any suggestions?
>
> James Lee
>
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