Operation must be an updatable query - Access - sql

Question

I'm writing a database and I simply want to update tblSchedule with the ItemNo from tblStock but I get an error when trying to run this:
Operation must be an updatable query
I can't seem to figure out why it's not working.
UPDATE [tblSchedule]
SET [tblSchedule].ItemNo =
(SELECT DISTINCT Item
FROM [tblStock], [tblSchedule]
WHERE [tblStock].Bookcode=[tblSchedule].[PartCode]
)`;
Any help would really be appreciated

Answer 1

You are missing a closing bracket in your SQL.
UPDATE [tblSchedule] Set
[tblSchedule].ItemNo = (
SELECT DISTINCT Item
FROM [tblStock], [tblSchedule -- Missing closing bracket
WHERE ((([tblStock].Bookcode)=[tblSchedule].[PartCode]))
)
Try closing the bracket on tblSchedule.
I do not have an Access database to test this on for you, though.

Answer 2

My guess is your inner SELECT is returning 2 records instead of one.
You can do this to validate.
SELECT Items.ItemNo, count(*) total
FROM
(
SELECT DISTINCT Sc.ItemNo, St.Item
FROM
[tblSchedule] Sc INNER JOIN
[tblStock] St ON Sc.PartCode = St.Bookcode
) as Items
GROUP BY Items.ItemNo
HAVING count(*) > 1;

Answer 3

Due to the simplicity of what I wanted I've gone down the Dlookup route which works successfully.
UPDATE [tblSchedule], [tblStock] SET [tblSchedule].ItemNo = DLookUp("Item","[tblStock]","[tblStock].Bookcode='" & [tblSchedule].[PartCode] & "'")
WHERE (([tblStock].[Bookcode]=[tblSchedule].[PartCode]));
It's probably not the best method but due to the small amount of records it updates (252) it works perfectly without any noticable time delay.
Thanks Again!
Chris