Working With A Result Set

Question

Hi Everybody,
I'm working on a application with will retrive data from a database for the past seven days, and then find the average for each of the days, the database is basically (id,date,hour,houraverage) - I can connect to the databse okay, but the problem i have is working with result set:
ResultSet rs = d.PerformQuery("0");
while (rs.next())
if (firsttime)
recorddate = rs.getString(2);
firsttime = false;
System.out.println("First Time");
numberofdays = 1;
if (!firsttime)
if (recorddate == rs.getString(2))
System.out.println(" Not First Time");
thisdaystotal = thisdaystotal + Float.parseFloat(rs.getString(4));
numberofrecords = numberofrecords + 1;
System.out.println(thisdaysaverage);
System.out.println(rs.getString(2));
if (recorddate != rs.getString(2))
thisdaystotal = thisdaystotal + Float.parseFloat(rs.getString(4));
numberofdays = numberofdays + 1;
thisdaysaverage = thisdaysaverage / numberofrecords;
recorddate = rs.getString(2);
for (int dayssofar=1;dayssofar<=numberofdays;dayssofar++)
System.out.println("Daily Average: " + dailyaverages[dayssofar]);
Basiclly the flaw in the program is that it can't tell if a record has the same date as the records before it - It can tell if they are different but not same, can anybody see any flaws in the logic?
Andrew

Answer 1

Why don't you try to use SQL to get what you need. For example, you can use:
SELECT DATE, AVG(HOURAVERAGE)
FROM TableName
WHERE DATE > 'DATE1'
GROUP BY DATE
(replace 'DATE1' with your specific date. If you are using Oracle replace it with: trunc(sysdate) -7 to get most recent 7 days).
Then you will get your averge values. There is no need to average them in your Java program.