Question

I am trying to JOIN multiple tables to the same value in a table. So I have the table ActivityPartyBase and it has a column PartyId. I want to join COntactId in ContactBase table to PartyId and AccountId in AccountBase table to PartyId. This is the code I am using and it doesn’t return anything. If I only join one it works. Any ideas?

SELECT DISTINCT Appointment.ScheduledStart, ActivityPartyBase.ActivityId
   , Appointment.ActivityId AS Expr1, ActivityPartyBase.ScheduledStart AS Expr2
   , Appointment.Subject, ActivityPartyBase.PartyId, ContactBase.ContactId
   , ContactBase.FullName
FROM Appointment
INNER JOIN ActivityPartyBase
   ON Appointment.ActivityId = ActivityPartyBase.ActivityId
INNER JOIN AccountBase ON ActivityPartyBase.PartyId = AccountBase.AccountId
LEFT OUTER JOIN ContactBase ON ActivityPartyBase.PartyId = ContactBase.ContactId
ORDER BY Appointment.ScheduledStart DESC

Answer 1

Your inner joins are filtering out results because there is no corresponding record on the joined table. I’ve always found the easiest way to debug is to “Select *” and use all LEFT JOINs. This will show you everything in your tables that relates to your main table; you should be able to look at your data and figure out what table is missing a record easily at that point.

To confirm that this is just a naming convention mismatch,

INNER JOIN AccountBase ON ActivityPartyBase.PartyId = AccountBase.AccountId

Are PartyID and AccountId the PK/FK?