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How to find out if there a Database ResultSet contains results

Posted on 1998-07-31
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Last Modified: 2010-03-30
I'm developing a servlet and I need to test whether there are any results in the ResultSet returned from my database query, if there aren't any I want to display an html page which indicates this.
What is the method to determine if there are results, I don't want to use 'next()' as this moves the resultset counter on one.

Please send me the code.

Thanks

Mel
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Question by:help_me
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3 Comments
 
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Expert Comment

by:msmolyak
ID: 1229589
I am afraid you have to call next() and cache the row values if the set is not empty.
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shchuka earned 150 total points
ID: 1229590
There's no other way to find out if the ResultSet is empty as to call the next() method.  Here's what you can do:

ResultSet = db.executeQuery(...);
if(rs == null) {
    //Error in the query string
}
if(!rs.next()) {
    //ResultSet is empty - do whatever you need
} else {
    do {
        //Do whatever you need with each row
    } while(rs.next());
}

This way you don't loose the first record by using next() to figure out whether the recordset is empty.
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LVL 5

Expert Comment

by:msmolyak
ID: 1229591
Statement.executeQuery() never returns null, a ResultSet object (possibly empty) is always returned.
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