update date column of a table in a database

Question

How can I update date column of a table in a database(mssql) by 1 year for 1st 1000 data, 2 year for 2nd 1000 data and so on... I know how to implement it by assigning temporary id but is there a way to update data in a loop manner??

for example: suppose if I have 6000 datas in table with joined_date column in range from 2012-01-01 to 2017-01-01 ordered in ascending order, I want to update first thousand rows increasing it by 1 year, 2nd thousand rows by 1 year as well and so on... If my first thousand data contain joined date on year 2012, I want to update it to 2013 and if my 2nd thousand data contain joined date on year 2012 to 2013 then I want to increment it by 1 as well.

Answer 1

We can try assigning a row number to your table, then use it to do the updates:

WITH cte AS (
    SELECT joined_date, ROW_NUMBER() OVER (ORDER BY joined_date) - 1 rn
    FROM yourTable
)

UPDATE cte
SET joined_date = DATEADD(year, (rn % 1000) + 1, joined_date);

The trick here is that the first 1000 rows, which would receive a row number of 0 up to and including 999, would have an rn % 1000 value of 0, to which we add 1 to get the number of years to add. The next 1000 records would have 2 years added, and so on.