Table table_name
| id |
|---|
| 1 |
| 2 |
| 3 |
| 4 |
| 4 |
| 5 |
| 6 |
| 6 |
| 7 |
| 7 |
| 7 |
| 8 |
| 9 |
| 9 |
| 10 |
Following SQL will give me the answer Demo but I need to hardcode each case and I need to know the MAX(id) in the first place.
SELECT id,
CASE
WHEN id > '0' AND id <= '3' THEN 1
WHEN id > '3' AND id <= '6' THEN 2
WHEN id > '6' AND id <= '9' THEN 3
WHEN id > '9' AND id <= '12' THEN 4
END AS groupid
FROM table_name
How to improve it without me hardcode using the CASE. Since id column will continue increasing and it will runout of case sometime later.
(SQL Server 2014 - build v12.0.6108.1)
Result:
| id | groupid |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 4 | 2 |
| 5 | 2 |
| 6 | 2 |
| 6 | 2 |
| 7 | 3 |
| 7 | 3 |
| 7 | 3 |
| 8 | 3 |
| 9 | 3 |
| 9 | 3 |
| 10 | 4 |
CodePudding user response：
SELECT id, CEILING(id/3.0) AS groupid FROM table_name