Fetch records where there is increase in Total_Sales.

Question

I have table like :-
Year Month Total_sales
2001     1     50000
2001     2     50000
2001     3     50000
2001 4     50000
2001     5     60000
2001     6     70000
2001     8     80000
2001     7     70000
I need the output like
Year Month Total_sales
2001     1     50000
2001     5     60000
2001     6     70000
2001     8     80000
It means, I want only those records where there is increase in Total_Sales.

Answer 1

SQL> With Data As
  2  (Select 2001 Year, 1 Month,  50000 Total_Sales From Dual Union All
  3  Select 2001, 2, 50000 From Dual Union All
  4  Select 2001 ,3, 50000 From Dual Union All
  5  Select 2001, 4, 50000 From Dual Union All
  6  Select 2001, 5, 60000 From Dual Union All
  7  Select 2001, 6, 70000 From Dual Union All
  8  Select 2001, 8, 80000 From Dual Union All
  9  Select 2001, 7, 70000 From Dual
10  )
11  Select * From (
12                 Select Year,
13                        Month,
14                        Case
15                        When Row_Number() Over(Order By Month) = 1 Then
16                        Total_Sales
17                        When (Lag(Total_Sales,1,Total_Sales) Over (Order By Total_Sales) < Total_Sales) Then
18                                                             Total_Sales
19                                                             Else
20                                                             Null
21                                                             End
22                        Total_Sales
23                                                      From Data
24                                                      )
25  where total_sales is not null;
      YEAR      MONTH TOTAL_SALES
      2001          1       50000
      2001          5       60000
      2001          6       70000
      2001          8       80000
SQL>