Updating multiple rows of a table at once

Hi,

I am writing a stored procedure which fills out all columns in a table, say Table A with one query except for one column, say column 'ABC' in that table. I have to load this left out column using a different query that is referring to some other tables. How can I update this column 'ABC' with all its rows of data coming from a different query?

Thanks!!

If you post an update with a create table and insert statements it would help... I think you want to update a table with a select from another table using a join... is that correct?

update customer c
set customer_name = (
select customer_name
from another_customer_table a
where a.customer_id = c.customer_id_from_original_customer_table
)
where c.customer_id in(select customer_id from another_customer_table)

The where clause is only needed if you don't want to update missing customer_ids to null.