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From Bob M <rgmatth...@orcon.net.nz>
Subject accessing records problem
Date Mon, 10 Feb 2014 09:19:45 GMT
Hi

I am calling derby within a larger java program....................

Step1: I allocate a database "Connection" object
Step2: I allocate a "Statement" object in the connection
Step 3: I execute a SQL SELECT query, the query result is returned in a
"ResultSet" object
so far so good (I update the latest database record, I add a new record and
I delete the oldest record
I then call a data mining program [Weka]
I setup a few Weka models etc......
I then wish to look at the last 100 records in my database, one at a time
The code I have currently is as follows:-
***********************
try {
Statement s = null;
ResultSet rs = null;
rs = s.executeQuery ("SELECT".................);
int k = 0
while (k < 101) {
rs.next();
...
...
}
k++;
}
}
catch (Exception e)
{
myConsole.getOut().println(e);
}

I get the following error:-
java.lang.NullPointerException

do I need to do something further to read my 100 records?

Bob M




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