#1644 - ENH: Improve batch flush when multiple "top level" (unrelated) types are persisted

src/test/java/org/tests/transaction/TestBatchModelFlush.java

@@ -1,10 +1,19 @@
 package org.tests.transaction;
 
 import io.ebean.BaseTestCase;
+import io.ebean.DB;
 import io.ebean.Ebean;
+import io.ebean.Transaction;
 import io.ebean.annotation.Transactional;
+import org.ebeantest.LoggedSqlCollector;
 import org.junit.Test;
 import org.tests.model.m2m.MnyB;
+import org.tests.model.m2m.MnyTopic;
+import org.tests.model.m2m.Role;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
 
 public class TestBatchModelFlush extends BaseTestCase {
 
@@ -30,4 +39,59 @@ public class TestBatchModelFlush extends BaseTestCase {
     // the rest is flushed on commit
     new MnyB("TestBatchModelFlush_5").save();
   }
+
+  @Test
+  public void multipleTopLevel_expect_singleFlush() {
+
+    LoggedSqlCollector.start();
+
+    // 2 unrelated "top level" beans being persisted
+    MnyB m0 = new MnyB("BatchMultipleTop_0");
+    MnyB m1 = new MnyB("BatchMultipleTop_1");
+    Role r0 = new Role("Role_0");
+    Role r1 = new Role("Role_1");
+
+    MnyTopic t0 = new MnyTopic("MnyTopic_0");
+    MnyTopic t1 = new MnyTopic("MnyTopic_1");
+
+    try (Transaction transaction = DB.beginTransaction()) {
+      transaction.setBatchMode(true);
+
+      m0.save();
+      DB.save(r0);
+      DB.save(t0);
+      DB.save(t1);
+
+      m1.save();
+      DB.save(r1);
+
+      transaction.commit();
+    }
+
+    List<String> sql = LoggedSqlCollector.stop();
+
+    // DEBUG io.ebean.SUM - txn[1001] BatchControl flush [MnyB:100 i:2, Role:101 i:2, MnyTopic:102 i:2]
+
+    assertThat(sql).hasSize(9);
+
+    // first saved to batch - (depth 100)
+    assertThat(sql.get(0)).contains("insert into mny_b");
+    assertThat(sql.get(1)).contains(" -- bind(BatchMultipleTop_0");
+    assertThat(sql.get(2)).contains(" -- bind(BatchMultipleTop_1");
+    // second saved to batch - (depth 101)
+    assertThat(sql.get(3)).contains("insert into mt_role");
+    assertThat(sql.get(4)).contains(" -- bind(");
+    assertThat(sql.get(5)).contains(" -- bind(");
+    // third saved to batch - (depth 102)
+    assertThat(sql.get(6)).contains("insert into mny_topic");
+    assertThat(sql.get(7)).contains(" -- bind(MnyTopic_0");
+    assertThat(sql.get(8)).contains(" -- bind(MnyTopic_1");
+
+    DB.delete(t0);
+    DB.delete(t1);
+    DB.delete(r0);
+    DB.delete(r1);
+    DB.delete(m0);
+    DB.delete(m1);
+  }
 }