title: Export datastore values using bulkloader with mapping tables (GAE - Google app engine)
body: <p>I have two tables with relationship as follows, May i know how to exports (csv file), child table with parentid using bulkloader.</p>
  
  <p>Table 1 : Parent</p>
  
  <pre><code>     @PersistenceCapable
       public class Parent{
       @PrimaryKey
       @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
       private Long parentId;
       @Persistent
       private String name;
       @Persistent
       private Child child;
  </code></pre>
  
  <p>Table 2 : Child</p>
  
  <pre><code>   public class Child implements StoreCallback {
      @PrimaryKey
      @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
      private Key childid;
      @Persistent
      private String name;
  </code></pre>