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Quering the ResultSet

kunal Jaggi
Greenhorn

Joined: Jun 17, 2003
Posts: 1
I am using Tomcat 4.1.12 on Windows 2000 professional. I am using the JDBC-ODBC Bridge driver to access the MS Access Database. I am having a problem while quering the ResultSet. Following is the code snippet that gives the problem :-
try{
rs=st.executeQuery("SELECT * FROM Users WHERE cID='"+f.getUserName()+"'");
if(rs==null)
userExists=false;
else
userExists=true;
}catch(SQLException e){
System.err.println(e);
}
I have checked the database, I know that there is no user id foe example “kunal”- even then the boolean variables evaluates to true. Can we query the ResultSet like that?
Regards,
Kunal Jaggi
Sun Certified Java 2 Programmer
Dirk Schreckmann
Sheriff

Joined: Dec 10, 2001
Posts: 7023
Java Facier,
Welcome to JavaRanch! We ain't got many rules 'round these parts, but we do got one. Please change your display name to comply with The JavaRanch Naming Policy.
Thanks pardner. Hope to see you 'round the Ranch!


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Lasse Koskela
author
Sheriff

Joined: Jan 23, 2002
Posts: 11962
    
    5
The ResultSet object returned by executeQuery() is never null. If there are no matching records, an empty ResultSet is returned.
Thus, you need to do something like this instead:


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Dirk Schreckmann
Sheriff

Joined: Dec 10, 2001
Posts: 7023
kunal_jaggi,
Thanks for changing your display name. Now, if you could just replace the underscore with a space, our naming policy would be satisfied.
Thanks.
Jeanne Boyarsky
author & internet detective
Marshal

Joined: May 26, 2003
Posts: 30764
    
156

The above example, could even be shorter. Checking for an empty result set is fast and easy.


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Kunal Goel
Greenhorn

Joined: Sep 08, 2002
Posts: 16
Thanks Lasse and Jeanne, it was something very obvious that I missed.
 
I agree. Here's the link: http://aspose.com/file-tools
 
subject: Quering the ResultSet