You might need to read data from more than one object at a time. The Data Integration Service generates relationship queries through SOQL to read data from related objects.
For example, you can read all accounts created by Tom Smith and the contacts associated with those accounts. You can use PowerExchange for Salesforce to create parent-to-child relationships that connect the objects.
Parent-to-child relationships exist between many types of objects. For example, Account is a parent of Contact, Assets, and Cases.
Use PowerExchange for Salesforce to read related objects. Each object can have one related object. For example, you can create a data object called Account Details. Select Account as the parent object, and either Contact or Opportunity as the child object. The relationship persists while creating a Salesforce data object read operation from the Salesforce data object called Account Details.