A query on inherited beans can be restricted to the subtype of one of its children (#1602)

ENH: A query on inherited beans can be restricted to the subtype of one of its children

src/test/java/org/tests/inheritance/TestInheritanceQuery.java

@@ -0,0 +1,47 @@
+package org.tests.inheritance;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import org.tests.inherit.ChildA;
+import org.tests.inherit.ChildB;
+import org.tests.inherit.Parent;
+import org.junit.Test;
+
+import io.ebean.BaseTestCase;
+import io.ebean.Ebean;
+import io.ebean.Query;
+
+public class TestInheritanceQuery extends BaseTestCase {
+
+  @Test
+  public void test() {
+    Parent a = new ChildA(90, "Bean A");
+    Parent b1 = new ChildB(91, "Bean B1");
+    Parent b2 = new ChildB(92, "Bean B2");
+
+    server().save(a);
+    server().save(b1);
+    server().save(b2);
+
+    Query<Parent> query = Ebean.find(Parent.class);
+
+    query.where().in("val",90, 91); // restrict to a & b1
+
+    assertThat(query.findList()).hasSize(2); // a & b1
+
+    Query<Parent> query2 = query.copy();
+    query2.setInheritType(ChildA.class);
+
+    assertThat(query.findList()).hasSize(2);
+    assertThat(query2.findList()).containsExactly(a);
+
+    query2.setInheritType(ChildB.class);
+    assertThat(query2.findList()).containsExactly(b1);
+
+    query2 = Ebean.find(Parent.class).setInheritType(ChildB.class);
+    assertThat(query2.findList()).contains(b1, b2);
+
+    Ebean.delete(a);
+    Ebean.delete(b1);
+    Ebean.delete(b2);
+  }
+}