Add Query alsoIfPresent() as helper for Nullable conditional expressions

ebean-api/src/main/java/io/ebean/QueryBuilder.java

@@ -44,6 +44,16 @@ public interface QueryBuilder<SELF extends QueryBuilder<SELF, T>, T> extends Que
    */
   SELF alsoIf(BooleanSupplier predicate, Consumer<SELF> apply);
 
+  /**
+   * Apply changes to the query when the supplied value is non-null.
+   * <p>
+   * Typically, the changes are extra predicates etc.
+   *
+   * @param value The value which when non-null the changes are applied
+   * @param apply The changes to apply to the query
+   */
+  SELF alsoIfPresent(@Nullable Object value, Consumer<SELF> apply);
+
   /**
    * Perform an 'As of' query using history tables to return the object graph
    * as of a time in the past.

ebean-core/src/main/java/io/ebeaninternal/server/query/DefaultFetchGroupQuery.java

@@ -219,6 +219,11 @@ public Query<T> alsoIf(BooleanSupplier predicate, Consumer<Query<T>> apply) {
     throw new RuntimeException("EB102: Only select() and fetch() clause is allowed on FetchGroup");
   }
 
+  @Override
+  public Query<T> alsoIfPresent(@Nullable Object value, Consumer<Query<T>> apply) {
+    throw new RuntimeException("EB102: Only select() and fetch() clause is allowed on FetchGroup");
+  }
+
   @Override
   public Query<T> usingTransaction(Transaction transaction) {
     throw new RuntimeException("EB102: Only select() and fetch() clause is allowed on FetchGroup");

ebean-core/src/main/java/io/ebeaninternal/server/querydefn/DefaultOrmQuery.java

@@ -307,6 +307,14 @@ public Query<T> alsoIf(BooleanSupplier predicate, Consumer<Query<T>> consumer) {
     return this;
   }
 
+  @Override
+  public Query<T> alsoIfPresent(@Nullable Object value, Consumer<Query<T>> consumer) {
+    if (value != null) {
+      consumer.accept(this);
+    }
+    return this;
+  }
+
   @Override
   public final void addSoftDeletePredicate(String softDeletePredicate) {
     if (softDeletePredicates == null) {

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

@@ -273,6 +273,14 @@ public final R alsoIf(BooleanSupplier predicate, Consumer<R> apply) {
     return root;
   }
 
+  @Override
+  public final R alsoIfPresent(@Nullable Object value, Consumer<R> apply) {
+    if (value != null) {
+      apply.accept(root);
+    }
+    return root;
+  }
+
   @Override
   public final R asOf(Timestamp asOf) {
     query.asOf(asOf);

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

@@ -36,7 +36,7 @@ void apply() {
       .query();
 
     q.findList();
-    assertThat(q.getGeneratedSql()).isEqualTo("select /* QueryAlsoIfTest.apply */ t0.id, t0.name from be_customer t0 where t0.name is not null and t0.status = ?");
+    assertThat(q.getGeneratedSql()).contains("from be_customer t0 where t0.name is not null and t0.status = ?");
   }
 
   @Test
@@ -48,7 +48,33 @@ void notApply() {
       .query();
 
     q.findList();
-    assertThat(q.getGeneratedSql()).isEqualTo("select /* QueryAlsoIfTest.notApply */ t0.id, t0.name from be_customer t0 where t0.name is not null");
+    assertThat(q.getGeneratedSql()).contains("from be_customer t0 where t0.name is not null");
+  }
+
+  @Test
+  void applyIfPresent() {
+    Object value = "yes";
+    var q = new QCustomer()
+      .select(name)
+      .name.isNotNull()
+      .alsoIfPresent(value, query -> query.status.equalTo(Customer.Status.GOOD))
+      .query();
+
+    q.findList();
+    assertThat(q.getGeneratedSql()).isEqualTo("select /* QueryAlsoIfTest.applyIfPresent */ t0.id, t0.name from be_customer t0 where t0.name is not null and t0.status = ?");
+  }
+
+  @Test
+  void notApplyIfPresent() {
+    Object value = null;
+    var q = new QCustomer()
+      .select(name)
+      .name.isNotNull()
+      .alsoIfPresent(value, query -> query.status.equalTo(Customer.Status.GOOD))
+      .query();
+
+    q.findList();
+    assertThat(q.getGeneratedSql()).isEqualTo("select /* QueryAlsoIfTest.notApplyIfPresent */ t0.id, t0.name from be_customer t0 where t0.name is not null");
   }
 
   @Test

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

@@ -33,4 +33,28 @@ void notApply() {
     query.findList();
     assertThat(query.getGeneratedSql()).isEqualTo("select t0.id, t0.name from o_customer t0");
   }
+
+  @Test
+  void applyIfPresent() {
+    ResetBasicData.reset();
+    Object value = "yes";
+    Query<Customer> query = DB.find(Customer.class)
+      .select("name")
+      .alsoIfPresent(value, 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 notApplyIfPresent() {
+    ResetBasicData.reset();
+    Object value = null;
+    Query<Customer> query = DB.find(Customer.class)
+      .select("name")
+      .alsoIfPresent(value, qy -> qy.where().isNotNull("name"));
+
+    query.findList();
+    assertThat(query.getGeneratedSql()).isEqualTo("select t0.id, t0.name from o_customer t0");
+  }
 }