From: Alan on
=DSum("[Amount6a6fs]","[Sales Analysis]","[Posting Date Period] = '" &
[cbMonth] & "' And [Revenue Stream Division] = 'Production' or [Revenue
Stream Division] = 'other' And ([Customer No] = 'C01317')")

every works apart from the last par customer no, the table name is correct
spelling,
the sun i'm getting is for everything not that specifc customer.

From: Douglas J. Steele on
I suspect the problem is due to precedence of Or vs And.

Try using IN

=DSum("[Amount6a6fs]","[Sales Analysis]","[Posting Date Period] = '" &
[cbMonth] & "' And [Revenue Stream Division] IN ('Production', 'other')
And ([Customer No] = 'C01317')")

or put parentheses around the OR

=DSum("[Amount6a6fs]","[Sales Analysis]","[Posting Date Period] = '" &
[cbMonth] & "' And ([Revenue Stream Division] = 'Production' or [Revenue
Stream Division] = 'other') And ([Customer No] = 'C01317')")

--
Doug Steele, Microsoft Access MVP
http://www.AccessMVP.com/djsteele
Co-author: Access 2010 Solutions, published by Wiley
(no e-mails, please!)



"Alan" <Alan(a)discussions.microsoft.com> wrote in message
news:2A6EDB79-88CA-4226-BE81-042141B5C1D7(a)microsoft.com...
> =DSum("[Amount6a6fs]","[Sales Analysis]","[Posting Date Period] = '" &
> [cbMonth] & "' And [Revenue Stream Division] = 'Production' or [Revenue
> Stream Division] = 'other' And ([Customer No] = 'C01317')")
>
> every works apart from the last par customer no, the table name is correct
> spelling,
> the sun i'm getting is for everything not that specifc customer.
>

From: Bob Quintal on
=?Utf-8?B?QWxhbg==?= <Alan(a)discussions.microsoft.com> wrote in
news:2A6EDB79-88CA-4226-BE81-042141B5C1D7(a)microsoft.com:

> =DSum("[Amount6a6fs]","[Sales Analysis]","[Posting Date Period] =
> '" & [cbMonth] & "' And [Revenue Stream Division] = 'Production'
> or [Revenue Stream Division] = 'other' And ([Customer No] =
> 'C01317')")
>
> every works apart from the last par customer no, the table name is
> correct spelling,
> the sun i'm getting is for everything not that specifc customer.
>
>

Parentheses are messed up. You have unnecessary ones around the
([Customer No] = 'C01317') but more importantly are missing a pair
around your two [Revenue Stream Division] = parameters.

Try
=DSum(
"[Amount6a6fs]",
"[Sales Analysis]",
"[Posting Date Period] = '" & [cbMonth] & "'
And
(
[Revenue Stream Division] = 'Production'
or [Revenue Stream Division] = 'other'
)
And [Customer No] = 'C01317'"
)

(all on 1 line, i've split it to show the grouping)