Question

I have a database table :

srno | passportnumber | flightnumber

I need a SQL query to update the srno such that the srno is same where ever passportnumber is the same.

I mean if passport abc123 and it occurs 4 times in the table then every time its serial number should be the same for all four.

Answer 1

;WITH CTE as 
(
select srno,passportnumber,flightnumbe,
row_number() over (partition by passportnumber order by (select 0)) as rnk 
from yourtable
)

update CTE set srno=rnk