Esta es una oportunidad en la oscuridad porque realmente no conocemos sus datos, pero si le gusta su consulta existente, es posible que simplemente la use dos veces pero con una cláusula where como esta:
SELECT
-- Common stuff?
ISNULL(Sales.ActivityId, Other.ActivityId), ISNULL(Sales.ScheduledStart, Other.ScheduledStart), ISNULL(Sales.OwnerIdName, Other.OwnerIdName), ISNULL(Sales.AccountIdName, Other.AccountIdName), ISNULL(Sales.new_ContactPersonName, Other.new_ContactPersonName), ISNULL(Sales.[Subject], Other.[Subject]), ISNULL(Sales.new_ColderNotes, Other.new_ColderNotes)
-- Sales stuff?
, Sales.AccountId, Sales.ContactId, Sales.SystemUserId, Sales.OptionalOwner, Sales.OptionalContact, Sales.OptionalAccount, Sales.PartyId, Sales.ParticipationTypeMask, Sales.RequiredContact, Sales.RequiredAccount, Sales.RequiredOwner, Sales.new_BusinessUnit
-- Other Stuff?
, Other.AccountId, Other.ContactId, Other.SystemUserId, Other.OptionalOwner, Other.OptionalContact, Other.OptionalAccount, Other.PartyId, Other.ParticipationTypeMask, Other.RequiredContact, Other.RequiredAccount, Other.RequiredOwner, Other.new_BusinessUnit
FROM
(
SELECT DISTINCT
Appointment.ActivityId, Appointment.ScheduledStart, Appointment.OwnerIdName, Contact.AccountIdName, Appointment.new_ContactPersonName,
Appointment.Subject, Appointment.new_ColderNotes, Account.AccountId, Contact_1.ContactId, SystemUser.SystemUserId, SystemUser.FullName AS OptionalOwner,
Contact_1.FullName AS OptionalContact, Account.Name AS OptionalAccount, ActivityParty.PartyId, ActivityParty.ParticipationTypeMask,
Contact_1.FullName AS RequiredContact, Account.Name AS RequiredAccount, SystemUser.FullName AS RequiredOwner, Account.new_BusinessUnit
FROM
Contact AS Contact_1 RIGHT OUTER JOIN
Account RIGHT OUTER JOIN
SystemUser RIGHT OUTER JOIN
Appointment INNER JOIN
ActivityParty ON Appointment.ActivityId = ActivityParty.ActivityId ON SystemUser.SystemUserId = ActivityParty.PartyId ON Account.AccountId = ActivityParty.PartyId ON
Contact_1.ContactId = ActivityParty.PartyId LEFT OUTER JOIN
Contact ON Appointment.new_ContactPerson = Contact.ContactId
-- Limit this part to Sales?
WHERE ParticipationTypeMask BETWEEN 1 AND 3
) as Sales
FULL OUTER JOIN
(
SELECT DISTINCT
Appointment.ActivityId, Appointment.ScheduledStart, Appointment.OwnerIdName, Contact.AccountIdName, Appointment.new_ContactPersonName,
Appointment.Subject, Appointment.new_ColderNotes, Account.AccountId, Contact_1.ContactId, SystemUser.SystemUserId, SystemUser.FullName AS OptionalOwner,
Contact_1.FullName AS OptionalContact, Account.Name AS OptionalAccount, ActivityParty.PartyId, ActivityParty.ParticipationTypeMask,
Contact_1.FullName AS RequiredContact, Account.Name AS RequiredAccount, SystemUser.FullName AS RequiredOwner, Account.new_BusinessUnit
FROM
Contact AS Contact_1 RIGHT OUTER JOIN
Account RIGHT OUTER JOIN
SystemUser RIGHT OUTER JOIN
Appointment INNER JOIN
ActivityParty ON Appointment.ActivityId = ActivityParty.ActivityId ON SystemUser.SystemUserId = ActivityParty.PartyId ON Account.AccountId = ActivityParty.PartyId ON
Contact_1.ContactId = ActivityParty.PartyId LEFT OUTER JOIN
Contact ON Appointment.new_ContactPerson = Contact.ContactId
-- Limit this part to Other?
WHERE ParticipationTypeMask BETWEEN 4 AND 6
) AS Other ON Sales.ActivityId = Other.ActivityId -- More cols for join?
