How to update Identity Column from ROW_NUMBER in sql server

Hi,

As per my knowledge it is not possible to update value of Identity column.
IDENTITY_INSERT is only work with Insert into statement....

but there is one work around

try
create table tableSalesQuotation
(
 Id int Identity(1,1),
 Name varchar(20)
)

Insert into tableSalesQuotation values('Tejas')
Insert into tableSalesQuotation values('Jignesh')
Insert into tableSalesQuotation values('Rakesh')

select * from tableSalesQuotation

select * into #dummy from tableSalesQuotation

delete from tableSalesQuotation

set IDENTITY_INSERT tableSalesQuotation ON

Insert Into tableSalesQuotation (Id,Name)
SELECT Row_Number() OVER (ORDER BY Name) as Id,name FROM #dummy

set IDENTITY_INSERT tableSalesQuotation OFF

hope this will help you.