Add Query alsoIf() to conditionally apply changes to a query

ebean-test/src/test/java/org/tests/query/TestQueryAlsoIf.java

@@ -0,0 +1,36 @@
+package org.tests.query;
+
+import io.ebean.DB;
+import io.ebean.Query;
+import org.junit.jupiter.api.Test;
+import org.tests.model.basic.Customer;
+import org.tests.model.basic.ResetBasicData;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class TestQueryAlsoIf {
+
+  int dummy = 1;
+
+  @Test
+  void apply() {
+    ResetBasicData.reset();
+    Query<Customer> query = DB.find(Customer.class)
+      .select("name")
+      .alsoIf(() -> dummy == 1, qy -> qy.where().isNotNull("name"));
+
+    query.findList();
+    assertThat(query.getGeneratedSql()).isEqualTo("select t0.id, t0.name from o_customer t0 where t0.name is not null");
+  }
+
+  @Test
+  void notApply() {
+    ResetBasicData.reset();
+    Query<Customer> query = DB.find(Customer.class)
+      .select("name")
+      .alsoIf(() -> dummy > 1, qy -> qy.where().isNotNull("name"));
+
+    query.findList();
+    assertThat(query.getGeneratedSql()).isEqualTo("select t0.id, t0.name from o_customer t0");
+  }
+}