I have a dataset like shown below (except the Ser_NO, this is the field i want to create).
+--------+------------+--------+
| CaseID | Order_Date | Ser_No |
+--------+------------+--------+
| 44 | 22-01-2018 | 1 |
+--------+------------+--------+
| 44 | 24-02-2018 | 3 |
+--------+------------+--------+
| 44 | 12-02-2018 | 2 |
+--------+------------+--------+
| 100 | 24-01-2018 | 1 |
+--------+------------+--------+
| 100 | 26-01-2018 | 2 |
+--------+------------+--------+
| 100 | 27-01-2018 | 3 |
+--------+------------+--------+
How can i achieve a serial number for each CaseId based on my dates. So the first date in a specific CaseID gets number 1, the second date in this CaseID gets number 2 and so on. I'm working with T-SQL btw,
I've tried a few things:
CASE
WHEN COUNT(CaseID) > 1
THEN ORDER BY (Order_Date)
AND Ser_no +1
END
Thanks in advance.