#2184 - Fix for findNative() with fetch() - convert fetch to fetchQuery with nativeSql

When using nativeSql (think of it as the "root query") we can't use "fetch joins" (FetchConfig.ofDefault()) as that means to prefer to use a SQL JOIN. In this nativeSql case we need to effectively automatically convert fetch() to fetchQuery()

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

@@ -1441,6 +1441,10 @@ public class DefaultOrmQuery<T> implements SpiQuery<T> {
 
   @Override
   public Query<T> fetch(String path, String properties, FetchConfig config) {
+    if (nativeSql != null && (config == null || config.isJoin())) {
+      // can't use fetch join with nativeSql (as the root query)
+      config = FETCH_QUERY;
+    }
     return fetchInternal(path, properties, config);
   }
 

ebean-core/src/test/java/org/tests/query/TestQueryFindNative.java

@@ -2,6 +2,7 @@ package org.tests.query;
 
 import io.ebean.BaseTestCase;
 import io.ebean.DB;
+import io.ebean.FetchConfig;
 import io.ebean.PagedList;
 import org.assertj.core.util.Lists;
 import org.ebeantest.LoggedSqlCollector;
@@ -280,7 +281,7 @@ public class TestQueryFindNative extends BaseTestCase {
     LoggedSqlCollector.start();
 
     List<Customer> result = DB.findNative(Customer.class, sql)
-            .fetch("contacts")
+            .fetch("contacts", "firstName, lastName")
             .findList();
 
     assertThat(result).isNotEmpty();
@@ -289,7 +290,7 @@ public class TestQueryFindNative extends BaseTestCase {
     if (isH2()) {
       assertThat(loggedSql).hasSize(2);
       assertThat(loggedSql.get(0)).contains("from o_customer");
-      assertThat(loggedSql.get(1)).contains("from contact");
+      assertThat(loggedSql.get(1)).contains("select t0.customer_id, t0.id, t0.first_name, t0.last_name from contact t0 where");
     }
   }
 
@@ -328,8 +329,9 @@ public class TestQueryFindNative extends BaseTestCase {
     LoggedSqlCollector.start();
 
     List<Customer> result = DB.findNative(Customer.class, sql)
+            // with nativeSql fetch (default) are converted to fetchQuery()
             .fetch("orders")
-            .fetch("contacts")
+            .fetch("contacts", FetchConfig.ofDefault())
             .findList();
 
     assertThat(result).isNotEmpty();