fix #821 date_histogram offset

Author: 石源

pom.xml

@@ -3,7 +3,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.nlpcn</groupId>
 	<artifactId>elasticsearch-sql</artifactId>
-	<version>6.5.1.0</version>
+	<version>6.5.1.1</version>
 	<packaging>jar</packaging>
 	<description>Query elasticsearch using SQL</description>
 	<name>elasticsearch-sql</name>

src/main/java/org/nlpcn/es4sql/query/maker/AggMaker.java

@@ -521,6 +521,9 @@ private DateHistogramAggregationBuilder dateHistogram(MethodField field) throws
                             dateHistogram.extendedBounds(new ExtendedBounds(bounds[0], bounds[1]));
                         }
                         break;
+                    case "offset":
+                        dateHistogram.offset(value);
+                        break;
 
                     case "alias":
                     case "nested":

src/test/java/org/nlpcn/es4sql/AggregationTest.java

@@ -371,8 +371,8 @@ public void countGroupByRange() throws IOException, SqlParseException, SQLFeatur
 	 */
 	@Test
 	public void countGroupByDateTest() throws IOException, SqlParseException, SQLFeatureNotSupportedException {
-        String result = MainTestSuite.getSearchDao().explain("select insert_time from online  group by date_histogram(field='insert_time','interval'='1.5h','format'='yyyy-MM','min_doc_count'=5) ").explain().toString();
-        Assert.assertTrue(result.replaceAll("\\s+", "").contains("{\"date_histogram\":{\"field\":\"insert_time\",\"format\":\"yyyy-MM\",\"interval\":\"1.5h\",\"offset\":0,\"order\":{\"_key\":\"asc\"},\"keyed\":false,\"min_doc_count\":5}"));
+        String result = MainTestSuite.getSearchDao().explain("select insert_time from online  group by date_histogram(field='insert_time','interval'='1.5h','format'='yyyy-MM','min_doc_count'=5,'offset'='+8h') ").explain().toString();
+        Assert.assertTrue(result.replaceAll("\\s+", "").contains("{\"date_histogram\":{\"field\":\"insert_time\",\"format\":\"yyyy-MM\",\"interval\":\"1.5h\",\"offset\":28800000,\"order\":{\"_key\":\"asc\"},\"keyed\":false,\"min_doc_count\":5}"));
 	}
 
     @Test