title: join 3 tables using graphql query
body: <p>I want to join 3 tables just like we do in mysql based on primary and foreign keys.</p>
  
  <p>Can I do such using graphql(<a href="http://graphql.org/" rel="nofollow noreferrer">http://graphql.org/</a>)
  My table structure along with graphql query is below. Thanks</p>
  
  <pre><code>query($companyId:String){
    Data{
      reach{
       department {
         departmentId
         departmentName
         description
       }
        companyDepartment(companyId:$companyId) {
          primaryId
          departmentId
          companyId
          createdDate
          modifiedDate
          modifiedBy
        }
        company(companyId:$companyId) {
          companyId
          companyName
        }
      }
    }
  }
  </code></pre>