From c74749f0f45e04dab605253fdb2c8f7e064ffe41 Mon Sep 17 00:00:00 2001
From: Samarth Jain <samarth@apache.org>
Date: Tue, 10 Mar 2020 15:06:03 -0700
Subject: [PATCH] Don't exclude null dimension values from the map based query
 response (#9438)

---
 .../apache/druid/query/groupby/ResultRow.java |  5 +--
 .../druid/query/groupby/ResultRowTest.java    | 44 +++++++++++++++++++
 2 files changed, 45 insertions(+), 4 deletions(-)

diff --git a/processing/src/main/java/org/apache/druid/query/groupby/ResultRow.java b/processing/src/main/java/org/apache/druid/query/groupby/ResultRow.java
index b31228c2db6..138b1e6aa20 100644
--- a/processing/src/main/java/org/apache/druid/query/groupby/ResultRow.java
+++ b/processing/src/main/java/org/apache/druid/query/groupby/ResultRow.java
@@ -163,10 +163,7 @@ public final class ResultRow
 
     for (int i = query.getResultRowDimensionStart(); i < row.length; i++) {
       final String columnName = resultRowOrder.get(i);
-
-      if (row[i] != null) {
-        map.put(columnName, row[i]);
-      }
+      map.put(columnName, row[i]);
     }
 
     return map;
diff --git a/processing/src/test/java/org/apache/druid/query/groupby/ResultRowTest.java b/processing/src/test/java/org/apache/druid/query/groupby/ResultRowTest.java
index e32e61e2d18..1e29e68c590 100644
--- a/processing/src/test/java/org/apache/druid/query/groupby/ResultRowTest.java
+++ b/processing/src/test/java/org/apache/druid/query/groupby/ResultRowTest.java
@@ -20,6 +20,15 @@
 package org.apache.druid.query.groupby;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.collect.ImmutableList;
+import org.apache.druid.data.input.MapBasedRow;
+import org.apache.druid.java.util.common.Intervals;
+import org.apache.druid.java.util.common.granularity.Granularities;
+import org.apache.druid.query.QueryRunnerTestHelper;
+import org.apache.druid.query.TableDataSource;
+import org.apache.druid.query.aggregation.CountAggregatorFactory;
+import org.apache.druid.query.dimension.DefaultDimensionSpec;
+import org.apache.druid.query.spec.MultipleIntervalSegmentSpec;
 import org.apache.druid.segment.TestHelper;
 import org.junit.Assert;
 import org.junit.Test;
@@ -34,4 +43,39 @@ public class ResultRowTest
     Assert.assertEquals(row, objectMapper.readValue("[1, 2, 3]", ResultRow.class));
     Assert.assertEquals(row, objectMapper.readValue(objectMapper.writeValueAsBytes(row), ResultRow.class));
   }
+
+  @Test
+  public void testMapBasedRowWithNullValues()
+  {
+    GroupByQuery query = new GroupByQuery(
+        new TableDataSource(QueryRunnerTestHelper.DATA_SOURCE),
+        new MultipleIntervalSegmentSpec(ImmutableList.of(Intervals.of("2011/2012"))),
+        null,
+        null,
+        Granularities.ALL,
+        ImmutableList.of(
+            new DefaultDimensionSpec("dim1", "dim1"),
+            new DefaultDimensionSpec("dim2", "dim2"),
+            new DefaultDimensionSpec("dim3", "dim3")
+        ),
+        ImmutableList.of(new CountAggregatorFactory("count")),
+        null,
+        null,
+        null,
+        null,
+        null
+    );
+
+    final ResultRow row = ResultRow.of("1", "2", null);
+    MapBasedRow mapBasedRow = row.toMapBasedRow(query);
+
+    // Let's make sure values are there as expected
+    Assert.assertEquals("1", mapBasedRow.getRaw("dim1"));
+    Assert.assertEquals("2", mapBasedRow.getRaw("dim2"));
+    Assert.assertNull(mapBasedRow.getRaw("dim3"));
+
+    // Also, let's make sure that the dimension with null value is actually present in the map
+    Assert.assertTrue(mapBasedRow.getEvent().containsKey("dim3"));
+  }
+
 }