SOQL Parent-to-child relationship query fetching Contacts and EDA child Addresses

Question

I'm trying to retrieve a Salesforce Contact and all their EDA Address records. The Contact lookup field details in the Address object, lists the Child Relationship Name as Addresses

Following Salesforce's documentation on Parent-to-child relationship queries here:

Parent-to-child relationship queries do not use dot notation:

SELECT LastName__c,
  (
    SELECT LastName__c
    FROM Daughters__r
  )
FROM Mother__c

I ran the following SOQL:

SELECT LastName,
(
    SELECT Name FROM Addresses__r
 )
from Contact WHERE Id = '003f400001XaiGAAAZ'

which fails with the following error

ERROR at Row:3:Column:22
Didn't understand relationship 'Addresses__r' in FROM part of query call. 
If you are attempting to use a custom relationship, be sure to append the 
'__r' after the custom relationship name. Please reference your WSDL or 
the describe call for the appropriate names.

Can someone point out how I can change my query to make it valid SOQL?

Answer 1

You have to query with the managed package's namespace prepended to the relationship name, when the relationship is packaged:

SELECT LastName,
(
    SELECT Name FROM hed__Addresses__r
 )
from Contact WHERE Id = '003f400001XaiGAAAZ'