#1572 - Support query.select("customer.id").findSingleAttributeList() ... in addition to the expected and working select("customer").findSingleAttributeList()

src/main/java/io/ebeaninternal/server/query/SqlTreeBuilder.java

@@ -419,15 +419,11 @@ public final class SqlTreeBuilder {
           } else {
             logger.error("property [" + propName + "] not found on " + desc + " for query - excluding it.");
           }
-
-        } else if (p.isEmbedded()) {
-          // add the embedded bean (and effectively
-          // all its properties)
+        } else if (p.isEmbedded() || (p instanceof STreePropertyAssoc && !queryProps.isIncludedBeanJoin(p.getName()))) {
+          // add the embedded bean or the *ToOne assoc bean.  We skip the check that the *ToOne propName maps to Id property ...
           selectProps.add(p);
-
         } else {
-          String m = "property [" + p.getFullBeanName() + "] expected to be an embedded bean for query - excluding it.";
-          logger.error(m);
+          logger.error("property [" + p.getFullBeanName() + "] expected to be an embedded or *ToOne bean for query - excluding it.");
         }
       }
 

src/test/java/org/tests/query/other/TestQuerySingleAttribute.java

@@ -359,6 +359,21 @@ public class TestQuerySingleAttribute extends BaseTestCase {
     assertThat(sqlOf(query)).contains("select distinct t0.customer_id from contact t0 order by t0.customer_id desc");
   }
 
+  @Test
+  public void distinctWithOrderByPkWithId() {
+
+    ResetBasicData.reset();
+
+    Query<Contact> query = Ebean.find(Contact.class)
+      .setDistinct(true)
+      .select("customer.id")
+      .orderBy().desc("customer.id");
+
+    query.findSingleAttributeList();
+
+    assertThat(sqlOf(query)).contains("select distinct t0.customer_id from contact t0 order by t0.customer_id desc");
+  }
+
   @Test
   public void distinctWithCascadedFetchOrderByPk() {