Added aggregation results in QueryResultsWrapper

pyreindexer/lib/include/queryresults_wrapper.h

@@ -29,6 +29,9 @@ class QueryResultsWrapper {
 		db_->FetchResults(*this);
 	}
 
+	const std::vector<reindexer::AggregationResult>& GetAggregationResults() const& { return qresPtr.GetAggregationResults(); }
+	const std::vector<reindexer::AggregationResult>& GetAggregationResults() const&& = delete;
+
 private:
 	friend DBInterface;
 

pyreindexer/lib/src/rawpyreindexer.cc

@@ -425,4 +425,37 @@ static PyObject *QueryResultsWrapperDelete(PyObject *self, PyObject *args) {
 
 	Py_RETURN_NONE;
 }
+
+static PyObject *GetAggregationResults(PyObject *self, PyObject *args) {
+	uintptr_t qresWrapperAddr;
+
+	if (!PyArg_ParseTuple(args, "k", &qresWrapperAddr)) {
+		return NULL;
+	}
+
+	QueryResultsWrapper *qresWrapper = getQueryResultsWrapper(qresWrapperAddr);
+
+	const auto &aggResults = qresWrapper->GetAggregationResults();
+	WrSerializer wrSer;
+	wrSer << "[";
+	for (size_t i = 0; i < aggResults.size(); ++i) {
+		if (i > 0) {
+			wrSer << ',';
+		}
+		aggResults[i].GetJSON(wrSer);
+	}
+	wrSer << "]";
+
+	PyObject *dictFromJson = nullptr;
+	try {
+		dictFromJson = PyObjectFromJson(reindexer::giftStr(wrSer.Slice()));	 // stolen ref
+	} catch (const Error &err) {
+		Py_XDECREF(dictFromJson);
+
+		return Py_BuildValue("is{}", err.code(), err.what().c_str());
+	}
+
+	return Py_BuildValue("isO", errOK, "", dictFromJson);
+}
+
 }  // namespace pyreindexer

pyreindexer/lib/src/rawpyreindexer.h

@@ -73,6 +73,7 @@ static PyObject *EnumNamespaces(PyObject *self, PyObject *args);
 
 static PyObject *QueryResultsWrapperIterate(PyObject *self, PyObject *args);
 static PyObject *QueryResultsWrapperDelete(PyObject *self, PyObject *args);
+static PyObject *GetAggregationResults(PyObject *self, PyObject *args);
 
 // clang-format off
 static PyMethodDef module_methods[] = {
@@ -98,6 +99,7 @@ static PyMethodDef module_methods[] = {
 
 	{"query_results_iterate", QueryResultsWrapperIterate, METH_VARARGS, "get query result"},
 	{"query_results_delete", QueryResultsWrapperDelete, METH_VARARGS, "free query results buffer"},
+	{"get_agg_results", GetAggregationResults, METH_VARARGS, "get aggregation results"},
 
 	{NULL, NULL, 0, NULL}
 };

pyreindexer/query_results.py

@@ -76,3 +76,11 @@ def _close_iterator(self):
 
         self.qres_iter_count = 0
         self.api.query_results_delete(self.qres_wrapper_ptr)
+
+
+    def get_agg_results(self):
+        """Returns aggregation results for the current query
+
+        """
+
+        return self.api.get_agg_results(self.qres_wrapper_ptr)

pyreindexer/tests/tests/test_sql.py

@@ -63,3 +63,18 @@ def test_sql_select_with_syntax_error(self, namespace, index, item):
         assert_that(calling(sql_query).with_args(namespace, query),
                     raises(Exception, matching=has_string(string_contains_in_order(
                         "Expected", "but found"))), "Error wasn't raised when syntax was incorrect")
+
+    def test_sql_select_with_aggregations(self, namespace, index, items):
+        # Given("Create namespace with item")
+        db, namespace_name = namespace
+        # When ("Insert items into namespace")
+        for _ in range(5):
+            db.item_insert(namespace_name, {"id": 100}, ["id=serial()"])
+
+        select_result = db.select(f'SELECT min(id),  max(id), avg(id) FROM {namespace_name}').get_agg_results()[2]
+        expected_values = {"min":1,"max":10,"avg":5.5}
+
+        # Then ("Check that returned agg results are correct")
+        for agg in select_result:
+            assert_that(agg['value'], equal_to(expected_values[agg['type']]),
+                        f"Incorrect aggregation result for {agg['type']}")