While loop on table rows in sql server using cursor

DECLARE @RID INT;

 ---- get table rid inside CUR_TEST

DECLARE CUR_TEST CURSOR FAST_FORWARD FOR SELECT RID FROM  tbl_User_Registration

OPEN CUR_TEST

FETCH NEXT FROM CUR_TEST INTO @RID

WHILE @@FETCH_STATUS = 0

BEGIN

declare @EmdilID varchar(100)='test@gmail.com'

   UPDATE tbl_User_Registration SET emialid = @EmdilID WHERE RID = @RID;

   FETCH NEXT FROM CUR_TEST INTO @RID

END

CLOSE CUR_TEST

DEALLOCATE CUR_TEST

GO