Github user cloud-fan commented on a diff in the pull request:
https://github.com/apache/spark/pull/9591#discussion_r44380218
--- Diff:
sql/core/src/test/java/test/org/apache/spark/sql/JavaDatasetSuite.java ---
@@ -366,4 +368,52 @@ public void testNestedTupleEncoder() {
context.createDataset(data3, encoder3);
Assert.assertEquals(data3, ds3.collectAsList());
}
+
+ @Test
+ public void testTypedAggregation() {
+ Encoder<Tuple2<String, Integer>> encoder = e.tuple(e.STRING(),
e.INT());
+ List<Tuple2<String, Integer>> data =
+ Arrays.asList(tuple2("a", 1), tuple2("a", 2), tuple2("b", 3));
+ Dataset<Tuple2<String, Integer>> ds = context.createDataset(data,
encoder);
+
+ GroupedDataset<String, Tuple2<String, Integer>> grouped = ds.groupBy(
+ new MapFunction<Tuple2<String, Integer>, String>() {
+ @Override
+ public String call(Tuple2<String, Integer> value) throws Exception
{
+ return value._1();
+ }
+ },
+ e.STRING());
+
+ Dataset<Tuple2<String, Integer>> agged = grouped.agg(new
IntSumOf().toColumn(e.INT(), e.INT()));
+ Assert.assertEquals(Arrays.asList(tuple2("a", 3), tuple2("b", 3)),
agged.collectAsList());
+
+ Dataset<Tuple4<String, Integer, Long, Long>> agged2 = grouped.agg(
+ new IntSumOf().toColumn(e.INT(), e.INT()),
+ (TypedColumn<Tuple2<String, Integer>, Long>) (Object)
expr("sum(_2)").as(e.LONG()),
+ (TypedColumn<Tuple2<String, Integer>, Long>) (Object) count("*"));
--- End diff --
java doesn't support contravariant in `TypedColumn`, which makes this typed
aggregate API hard to use at java side.
cc @marmbrus @rxin
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
