Error running Update SQL, which has a table join

Question

I'm running oracle 10g.
I have two tables (described below):
notes table:
cust - varchar(10)
group -varchar(10)
opportunity_id - varchar (10)
activity table:
cust - varchar(10)
group - varchar(10)
i_ref_no - integer
i_vendor_control - varchar(15)
create_date - date
I want to update the first_name and last_name columns in the notes table with the first_name and last_name columns in the activity, while doing an inner join on the opportunity_id and i_vendor_control. Only update if first_name and last_name are both null in the notes table AND if the create date is greater than 1/1/13 in the activity table and the i_ref_no is between certain values.
Here's my SQL:
update notes
set (notes.i_cust, notes.i_grup) =
(select activity.i_cust, activity.i_grup
     from activity
where notes.opportunity_id = activity.i_vendor_control
     and activity.d_crea = '04/23/13'
     and activity.i_ref_no between 871206 and 871210)
where notes.i_cust IS NULL
and notes.i_grup IS NULL
and notes.opportunity_id in (select activity.i_vendor_control from activity
          where activity.d_crea = '04/23/13'
          and activity.i_ref_no between 871206 and 871210)
Can someone tell me why this SQL gets a syntax error? I can run the nested select statements separately and they work fine, but when i run this entire SQL, i get a syntax error. Can anyone see the syntax error? Or is there a better way to write this? All i'm doing is updating the first and last names in the first table with that of the second table.

Answer 1

I think this should suffice
update notes
set (notes.i_cust, notes.group) =
(select activity.i_cust, activity.group
from activity
where notes.opportunity_id = activity.i_vendor_control
and activity.create_date = '04/23/13'
and activity.i_ref_no between 871206 and 871210)
where notes.i_cust IS NULL
and notes.group IS NULL
and notes.opportunity_id in (select activity.i_vendor_control from activity
where activity.create_date = '04/23/13'
and activity.i_ref_no between 871206 and 871210)
Why do you need an extra clause with IN operator for the same where condition?
Is it because its not an update for the entire table? If so then have the outer clause using exists as it will perform better