Bug fix, order by doesn't work when group by field has alias

integ-test/src/test/java/com/amazon/opendistroforelasticsearch/sql/legacy/AggregationIT.java

@@ -501,6 +501,31 @@ public void orderByAliasDescTest() throws IOException {
         rows(493));
   }
 
+  @Test
+  public void orderByGroupFieldWithAlias() throws IOException {
+    // ORDER BY field name
+    JSONObject response = executeJdbcRequest(String.format("SELECT gender as g, COUNT(*) as count "
+        + "FROM %s GROUP BY gender ORDER BY gender", TEST_INDEX_ACCOUNT));
+
+    verifySchema(response,
+        schema("g", "g", "text"),
+        schema("count", "count", "integer"));
+    verifyDataRowsInOrder(response,
+        rows("f", 493),
+        rows("m", 507));
+
+    // ORDER BY field alias
+    response = executeJdbcRequest(String.format("SELECT gender as g, COUNT(*) as count "
+        + "FROM %s GROUP BY gender ORDER BY g", TEST_INDEX_ACCOUNT));
+
+    verifySchema(response,
+        schema("g", "g", "text"),
+        schema("count", "count", "integer"));
+    verifyDataRowsInOrder(response,
+        rows("f", 493),
+        rows("m", 507));
+  }
+
   @Test
   public void limitTest() throws IOException {
     JSONObject response = executeJdbcRequest(String.format("SELECT COUNT(*) FROM %s " +

integ-test/src/test/resources/correctness/bugfixes/765.txt

@@ -0,0 +1 @@
+SELECT Carrier AS c, COUNT(*) AS count FROM kibana_sample_data_flights GROUP BY Carrier ORDER BY Carrier

legacy/src/main/java/com/amazon/opendistroforelasticsearch/sql/legacy/query/maker/AggMaker.java

@@ -74,6 +74,9 @@
 
 public class AggMaker {
 
+    /**
+     * The mapping bettwen group fieldName or Alias to the KVValue.
+     */
     private Map<String, KVValue> groupMap = new HashMap<>();
     private Where where;
 
@@ -108,7 +111,11 @@ public AggregationBuilder makeGroupAgg(Field field) throws SqlParseException {
         } else {
             String termName = (Strings.isNullOrEmpty(field.getAlias())) ? field.getName() : field.getAlias();
             TermsAggregationBuilder termsBuilder = AggregationBuilders.terms(termName).field(field.getName());
-            groupMap.put(termName, new KVValue("KEY", termsBuilder));
+            final KVValue kvValue = new KVValue("KEY", termsBuilder);
+            groupMap.put(termName, kvValue);
+            // map the field name with KVValue if it is not yet. The use case is when alias exist,
+            // the termName is different with fieldName, both of them should be included in the map.
+            groupMap.putIfAbsent(field.getName(), kvValue);
             return termsBuilder;
         }
     }