Merge pull request #3348 from ebean-orm/feature/3313-fetchGroup-with-config

#3313 Ability to configure fetch batch size when using FetchGroups and query beans

ebean-querybean/src/main/java/io/ebean/typequery/TQAssocBean.java

@@ -108,6 +108,18 @@ public abstract class TQAssocBean<T, R, QB> extends TQAssoc<T, R> {
     return fetchWithProperties(FETCH_DEFAULT, properties);
   }
 
+
+  /**
+   * Fetch this association with config for the type of fetch and the specified properties.
+   *
+   * @param config Fetch configuration to define the type of fetch to use
+   * @param properties The properties to fetch
+   */
+  @SafeVarargs @SuppressWarnings("varargs")
+  public final R fetch(FetchConfig config, TQProperty<QB,?>... properties) {
+    return fetchWithProperties(config, properties);
+  }
+
   /**
    * Eagerly fetch this association using a 'query join' loading the specified properties.
    */

ebean-querybean/src/test/java/org/querytest/QOrderTest.java

@@ -1,6 +1,7 @@
 package org.querytest;
 
 import io.ebean.DB;
+import io.ebean.FetchConfig;
 import io.ebean.FetchGroup;
 import io.ebean.Query;
 import io.ebean.test.LoggedSql;
@@ -8,6 +9,7 @@ import org.example.domain.Customer;
 import org.example.domain.Order;
 import org.example.domain.OrderDetail;
 import org.example.domain.otherpackage.PhoneNumber;
+import org.example.domain.query.QContact;
 import org.example.domain.query.QCustomer;
 import org.example.domain.query.QOrder;
 import org.example.domain.query.QOrderDetail;
@@ -26,10 +28,17 @@ public class QOrderTest {
 
   private static final QOrder or = QOrder.alias();
 
+  private static final QContact co = QContact.alias();
+
   private static final FetchGroup<Customer> fgC = QCustomer.forFetchGroup()
     .select(cu.name, cu.phoneNumber)
     .buildFetchGroup();
 
+  private static final FetchGroup<Customer> fgCustomerWithContacts = QCustomer.forFetchGroup()
+    .select(cu.name, cu.phoneNumber)
+    .contacts.fetch(FetchConfig.ofQuery(1000), co.firstName, co.lastName, co.email)
+    .buildFetchGroup();
+
   private static final FetchGroup<Order> fgNested1 = QOrder.forFetchGroup()
     .select(or.status, or.shipDate)
     .customer.fetch(fgC)
@@ -70,6 +79,20 @@ public class QOrderTest {
     DB.delete(customer);
   }
 
+  @Test
+  void fetchQueryWithBatch() {
+    LoggedSql.start();
+
+    new QCustomer()
+      .select(fgCustomerWithContacts)
+      .findList();
+
+    final List<String> sql = LoggedSql.stop();
+    assertThat(sql).hasSize(2);
+    assertThat(sql.get(0)).contains("select t0.id, t0.name, t0.phone_number from be_customer t0");
+    assertThat(sql.get(1)).contains("select t0.customer_id, t0.id, t0.first_name, t0.last_name, t0.email from be_contact t0 where");
+  }
+
   @Test
   public void fetchCache() {