Update SQL Server cell data with the data of next record

Question

I have to update the data of one of my SQL Server table that was mistakenly updated, and this caused data of one row's cell to over-write the next. Following is an example of what the table should have been in correct state:

FirstName      LastName     EmailID
--------------------------------------------------
abc            xyz          abc.xyz@something.com
def            321          def.321@something.com
ghi            123          ghi.123@something.com

Mistakenly the data has become:

FirstName   LastName    EmailID
---------------------------------------------
abc         xyz         something
def         321         abc.xyz@something.com
ghi         123         def.321@something.com

I know that the last one record will not be found but atleast other should be restored correctly

Answer 1

assuming your table is ordered by firstName, lastName you can use this:

declare @contact as table (firstName varchar(255), lastName varchar(255), emailID varchar(255))
insert into @contact (firstName, lastName, emailID)
values
    ('abc', 'xyz', 'something')
    ,('def', '321', 'abc.xyz@something.com')
    ,('ghi', '123', 'def.321@something.com');


with contactCTE(rowNo, firstName, lastName, emailID) 
as
(
    select 
        ROW_NUMBER() OVER (ORDER BY firstName, lastName DESC)
        ,firstName 
        ,lastName 
        ,emailID 
    from
        @contact 
)
update c1   
set
    emailID = c2.emailID 
from 
    contactCTE c1
    inner join contactCTE c2 on c1.rowNo +1 = c2.rowNo;

select * from  @contact     

If your data is ordered differently just modify the ORDER BY part in contactCTE to reflect this