Question

have a temptable as follows

 1. id  empid  triggerstatus
     1   2881     null 
     2   2881     null
     3   2881     null
     4   2882     null

i need a sql query which will update the triggerstatus dynamically
to triggerstatus+1 if the empid is repected twice,trice,etc.

my result should look as

id  empid  triggerstatus
1   2881     1
2   2881     2
3   2881     3
4   2882     1

Answer 1

If you have SQL Server 2005+ you can use a CTE and ROW_NUMBER Windowing function:

WITH cte AS
(
   SELECT id, empId, triggerStatus
      , ROW_NUMBER() OVER (PARTITION BY empId ORDER BY id ASC) AS RowNumber
   FROM yourTable
)
UPDATE t
SET triggerStatus = RowNumber
FROM yourTable AS t
INNER JOIN cte ON t.id = cte.id

You may want to add a WHERE clause if there are some records that you do not want to update triggerStatus for.