How to do groupby in java

[Vasudevan Gopalan]

I am getting records from database like this in a while loop

  
         EmpId    some column
         -----    ------
           1        25 
           1        30
           2        90
           3        45
           3        90          
 

I need to get the sum of second column grouped by empid .I can achieve this by giving group by clause in sql query but i cant give group by clause in query since the query is a union query .How can we group the records using java .My desired output for above query is

         EmpId    some column
         -----    ------
           1        55 
           2        90
           3        135

Is there any Util class for group by?.

Regards
vasu

[Alex Leung]

Hi,
I have not touch JDBC for a while now, but what I know is you have to execute the SQL statement on the database itself from java then retrieve the data into the program, using java.sql
so you need to execute something like this on the database inside java:
SELECT EmpId, COUNT(*) AS some_column
FROM table_name
GROUP BY EmpId
ORDER BY EmpId
hope this helps.