# Identifying Parent and Child Relationships

Identify parent-child relationships by viewing Entity Relationship Diagrams (ERD) or by examining the enterprise WSDL for your organization.

You can identify parent-child relationships by viewing a diagram in the [Salesforce Architect Diagram Gallery](https://architect.salesforce.com/diagrams). However, not all parent-child relationships are exposed in SOQL, so to be sure you can query on a parent-child relationship by issuing the appropriate describe call. The results contain parent-child relationship information.

You can also examine the enterprise WSDL for your organization:

- To find the names of child relationships, look for entries that contain the plural form of a child object and end with `type="tns:QueryResult"`. For example, from Account:

  ```xml
               <complexType name="Account">
                  <complexContent>
                    <extension base="ens:sObject">
                      <sequence>
                        ...
                        <element name="Contacts" nillable="true" minOccurs="0"
                                       type="tns:QueryResult"/>
                        ...
                      </sequence>
                    </extension>
                  </complexContent>
                </complexType>
  ```

  In the example above, the child relationship name `Contacts` is in the entry for its parent Account.

- For the parent of an object, look for a pair of entries, such as `AccountId` and `Account`, where the ID field represents the parent object referenced by the ID, and the other represents the contents of the record. The parent entry has a non-primitive type, `type="ens:Account"`.

  ```xml
                <complexType name="Opportunity">
                  <complexContent>
                    <extension base="ens:sObject">
                      <sequence>
                        ...
                        <element name="Account" nillable="true" minOccurs="0"
                                type="ens:Account"/>
                        <element name="AccountId" nillable="true" minOccurs="0"
                                type="tns:ID"/>
                        ...
                      </sequence>
                    </extension>
                   </complexContent>
                 </complexType>

  ```

  :::note
  Not all relationships are exposed in the API. The most reliable method for identifying relationships is to execute a `describeSObjects()` call. You can use the [AJAX Toolkit](https://developer.salesforce.com/docs/atlas.en-us.ajax.meta/ajax/) to quickly execute test calls.
  :::

- For custom objects, look for a pair of entries with the relationship suffix `__r`:

  ```xml
            <complexType name="Mother__c">
             <complexContent>
              <extension base="ens:sObject">
               <sequence>
                 ...
                 <element name="Daughters__r" nillable="true" minOccurs="0"
                       type="tns:QueryResult"/>
                 <element name="FirstName__c" nillable="true" minOccurs="0"
                       type="xsd:string"/>
                 <element name="LastName__c" nillable="true" minOccurs="0"
                       type="xsd:string"/>
                 ...
                </sequence>
               </extension>
              </complexContent>
              </complexType>
  ```

  ```xml
            <complexType name="Daughter__c">
             <complexContent>
              <extension base="ens:sObject">
               <sequence>
                 ...
                 <element name="Mother_of_Child__c" nillable="true" minOccurs="0"
                       type="tns:ID"/>
                 <element name="Mother_of_Child__r" nillable="true" minOccurs="0"
                       type="xsd:string"/>
                 <element name="LastName__c" nillable="true" minOccurs="0"
                       type="ens:Mother__c"/>
                 ...
                </sequence>
               </extension>
              </complexContent>
             </complexType>
  ```