I am trying to carry forward the previous state of data wherever data is not available. For example, I have following data;
Month | Order | Amount
1 | Item1 | 100
1 | Item2 | 200
1 | Item3 | 300
2 | NULL | NULL
3 | Item4 | 100
4 | NULL | NULL
5 | NULL | NULL
6 | Item1 | 100
| Month | Order | Amount |
|---|---|---|
| 1 | Item1 | 100 |
| 1 | Item2 | 200 |
| 1 | Item3 | 300 |
| 2 | NULL | NULL |
| 3 | Item4 | 100 |
| 4 | NULL | NULL |
| 5 | NULL | NULL |
| 6 | Item1 | 100 |
So in the above example I want to use 1st month's information to be carry forwarded as it is for 2nd month. Also since 3rd month's information is available then use it for the month 4 and 5. Hence the output will be following:
Month | Order | Amount
1 | Item1 | 100
1 | Item2 | 200
1 | Item3 | 300
2 | Item1 | 100
2 | Item2 | 200
2 | Item3 | 300
3 | Item4 | 100
4 | Item4 | 100
5 | Item4 | 100
6 | Item1 | 100
| Month | Order | Amount |
|---|---|---|
| 1 | Item1 | 100 |
| 1 | Item2 | 200 |
| 1 | Item3 | 300 |
| 2 | Item1 | 100 |
| 2 | Item2 | 200 |
| 2 | Item3 | 300 |
| 3 | Item4 | 100 |
| 4 | Item4 | 100 |
| 5 | Item4 | 100 |
| 6 | Item1 | 100 |