I've got a Junction Object, Product_Dependencies_Association which has a Mast-Detail Relationship to a My_Custom_Product__c Object named Child_Product__c and a Lookup relationship (not Master-Detail) that also points to a My_Custom_Product__c Object named Parent_Product__c.

The Child_Product__c relationship's Child Relationship Name is Child_Product_Relationship.

My question is, why won't the following query work?

[select (SELECT Name FROM Child_Product_Relationship__r) FROM Product_Dependencies_Association__c]

It fails with `Error:

Compile Error: Didn't understand relationship 'Child_Product_Relationship__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.`

Interesting to note: https://workbench.developerforce.com reports the relationshipName for the Child_Product__c relationship as Child_Product__r, not Child_Product_Relationship__r as I defined within the Salesforce UI. I've also tried Child_Product__r and Child_Product_Relationship in the query and get the same error.

Details of the Child_Product field, as requested: Child Product field

  • Loog at the field Child_Product__c and what does it say for the Child Relationship name. Could you have a type? Can you attach a screenshot of the field detail
    – Eric
    Jun 17, 2015 at 18:31
  • @Eric, the Child Relationship Name is Child_Product_Relationship. I don't know what you mean by "Could you have a type?". Edited my question with screenshot you requested. Thanks! Jun 17, 2015 at 18:52
  • Can you post a screenshot of what Workbench shows under the Child Relationships for your Product_Dependencies_Association__c object? I'm wondering if perhaps you have the relationshps mixed and Product_Dependencies_Association__c is on the Detail end of the Master/Detail relationship?
    – dBeltowski
    Jun 17, 2015 at 19:04
  • what is the plural name does it say Child Product Relationship (or) Child Product Relationships, try Child_Product_Relationships__r
    – Rao
    Jun 17, 2015 at 19:07
  • @DougB, hm, there are no relevant Child Relationships for the Product_Dependencies_Association__c object. The child relationship does show up for the My_Custom_Product__c object. Should I flip them around, and if so how? Jun 17, 2015 at 19:10

2 Answers 2


Based on your screenshot I suspect "My_Custom_Project__c" is the parent in the relationship and Product_Dependencies_Association__c is the child in the relationship.

The below query should confirm this suspicion.

[SELECT Name (SELECT Name FROM Child_Product_Relationship__r) FROM My_Custom_Project__c ]

If this is was not your intent remove the "Child_Object__c" field from the "Product_Dependencies_Association__c" object. Instead create it on the "My_Custom_Project__c" as a Master/Detail looking up to the "Product_Dependencies_Association__c" object

  • Yes, this works! It just seems superfluous to have to query the product when I don't care about the product. Unfortunately, I cannot add a Master/Detail Relationship to the My_Custom_Project__c object as it is a Managed Object. Jun 17, 2015 at 19:16
  • @DavidMurdoch Glad I could help.
    – dBeltowski
    Jun 17, 2015 at 19:18

The child relationship name "Child_Product_Relationship" is the name of the relationship to the Product_Dependencies_Association__c child records from the point of view of the My_Custom_Product__c parent record.

You're trying to use it from the opposite direction in your query which is why you're receiving the error about an unknown relationship name. That name exists on the parent (master: My_Custom_Product__c) and points to the list of its children (detail: Product_Dependencies_Association__c).

    , Name
    , (SELECT Id
          , Name 
       FROM Child_Product_Relationship__r) 
 FROM My_Custom_Product__c]

This query produces a list of My_Custom_Product__c records and a list of Product_Dependencies_Association__c children under each one of them. The list of these child records is referred to by the name Child_Product_Relationship__r.

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