Analytic function Issue

Question

Create table Example as
select 124 Emp_Id, 350 Amt from dual
Union select 123 Emp_Id, 200 Amt from dual
Union select 124 Emp_Id, 350 Amt from dual
Union select 125 Emp_Id, 250 Amt from dual
Union select 126 Emp_Id, 250 Amt from dual
Union select 127 Emp_Id, 100 Amt from dual
I am having the dataet like
Emp_Id TotalAmt
123 200
124 350
125 250
126 250
127 100
with query
SELECT EMP_ID,Amt,
SUM (Amt) OVER ( ORDER BY Amt DESC) AS total
FROM Example
WHERE Amt > 0 ;
query return
Emp_Id Amt Total
124 350 350
*125 250 850*
*126 250 850*
123 200 1050
127 100 1150
in this second row total amount added with third row.
Excepted Output is
Emp_Id Amt Total
124 350 350
125 250 600
126 250 850
123 200 1050
127 100 1150

Answer 1

Hi,
Add more expressions to the analytic ORDER BY cluase so that there are no ties in the ordering.
For example:
SELECT      EMP_ID,Amt,
     SUM (Amt) OVER ( ORDER BY  Amt           DESC
                ,        emp_id          -- Added
                 ) AS total
FROM      Example
WHERE      Amt      > 0 ;"SUM (x) OVER (ORDER BY y)" means you will get the same result for each value of y, and a different result only if y is different.
If there is nothing else unique about each row, you can use ROWNUM.
This behavior is a consequence of the default windowing clause "RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW". "RANGE" refers to the value(s) in the ORDER BY clause. SBH (above) gave another solution which explicitly changes the wondowing from RANGE to ROWS, meaning you can get a separate result for each row, regardless of the value(s) of y.
Edited by: Frank Kulash on Jul 12, 2010 5:40 AM