how to add new column like existing one?

What's the best way to add a new column Y to an existing table that already
has existing column X, and I want Y to be x+3? I need to actually save the
value in the database, so yes, I do want a new column.On Sat, 29 Jan 2005 21:44:12 GMT, AFN wrote:

>What's the best way to add a new column Y to an existing table that already
>has existing column X, and I want Y to be x+3? I need to actually save th
e
>value in the database, so yes, I do want a new column.
>
Hi AFN,
ALTER TABLE MyTable
ADD Y AS x+3
Best, Hugo
--
(Remove _NO_ and _SPAM_ to get my e-mail address)|||Add the column, run an update statement:
create table tablename
(
x int
)
insert into tablename values (1)
insert into tablename values (2)
insert into tablename values (3)
go
alter table tablename add y int null
go
update tablename
set y = x+3
go
alter table tablename alter column y in not null
go
Will you want all new values to be x + 3, or just initially? If the ONLY
values ever to be stored would be then you can use a computed column and
index it (this will persist the values so it doesn't have to be calculated
except the first time:
alter table tablename add y1 as (x+3)
create index tablnamePersistY1 on tablename(y1)
----
Louis Davidson - drsql@.hotmail.com
SQL Server MVP
Compass Technology Management - www.compass.net
Pro SQL Server 2000 Database Design -
http://www.apress.com/book/bookDisplay.html?bID=266
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"AFN" < newsDELETETHECAPSgroupaccount@.DELETETHIS
yahoo.com> wrote in message
news:MsTKd.4579$e11.4113@.twister.socal.rr.com...
> What's the best way to add a new column Y to an existing table that
> already
> has existing column X, and I want Y to be x+3? I need to actually save
> the
> value in the database, so yes, I do want a new column.
>