resolves #2078: sort YdbResults via ColumnHints

ydb/core/kqp/query_compiler/kqp_query_compiler.cpp

@@ -520,12 +520,27 @@ class TKqpQueryCompiler : public IKqpQueryCompiler {
                 return false;
             }
 
-            auto resultMeta = queryBindingProto.MutableResultSetMeta();
+            auto resultMetaColumns = queryBindingProto.MutableResultSetMeta()->Mutablecolumns();
+            for (size_t i = 0; i < kikimrProto.GetStruct().MemberSize(); i++) {
+                resultMetaColumns->Add();
+            }
+
+            THashMap<TString, int> columnOrder;
+            columnOrder.reserve(kikimrProto.GetStruct().MemberSize());
+            if (!txResult.GetColumnHints().empty()) {
+                YQL_ENSURE(txResult.GetColumnHints().size() == (int)kikimrProto.GetStruct().MemberSize());
+                for (int i = 0; i < txResult.GetColumnHints().size(); i++) {
+                    const auto& hint = txResult.GetColumnHints().at(i);
+                    columnOrder[TString(hint)] = i;
+                }
+            }
 
+            int id = 0;
             for (const auto& column : kikimrProto.GetStruct().GetMember()) {
-                auto columnMeta = resultMeta->add_columns();
-                columnMeta->set_name(column.GetName());
-                ConvertMiniKQLTypeToYdbType(column.GetType(), *columnMeta->mutable_type());
+                int bindingColumnId = columnOrder.count(column.GetName()) ? columnOrder.at(column.GetName()) : id++;
+                auto& columnMeta = resultMetaColumns->at(bindingColumnId);
+                columnMeta.Setname(column.GetName());
+                ConvertMiniKQLTypeToYdbType(column.GetType(), *columnMeta.mutable_type());
             }
         }
 

ydb/core/kqp/ut/pg/kqp_pg_ut.cpp

@@ -1,4 +1,8 @@
-#include "ydb/public/sdk/cpp/client/ydb_proto/accessor.h"
+#include <ydb/core/kqp/common/events/events.h>
+#include <ydb/core/kqp/common/simple/services.h>
+#include <ydb/core/kqp/executer_actor/kqp_executer.h>
+
+#include <ydb/public/sdk/cpp/client/ydb_proto/accessor.h>
 #include <ydb/core/kqp/ut/common/kqp_ut_common.h>
 
 #include <ydb/library/yql/parser/pg_catalog/catalog.h>
@@ -9,7 +13,6 @@
 
 
 extern "C" {
-#include "postgres.h"
 #include "catalog/pg_type_d.h"
 }
 
@@ -3853,7 +3856,7 @@ Y_UNIT_TEST_SUITE(KqpPg) {
                     INSERT INTO RecompileTable (id) VALUES (1);
                 )", NYdb::NQuery::TTxControl::BeginTx().CommitTx(), settings).ExtractValueSync();
                 UNIT_ASSERT_VALUES_EQUAL_C(result.GetStatus(), EStatus::SUCCESS, result.GetIssues().ToString());
-            
+
                 result = db.ExecuteQuery(R"(
                     DROP TABLE RecompileTable;
                 )", NYdb::NQuery::TTxControl::NoTx(), settings).ExtractValueSync();
@@ -4037,6 +4040,59 @@ Y_UNIT_TEST_SUITE(KqpPg) {
             CompareYson(R"([])", FormatResultSetYson(result.GetResultSet(0)));
         }
    }
+
+      Y_UNIT_TEST(ExplainColumnsReorder) {
+        TPortManager tp;
+        ui16 mbusport = tp.GetPort(2134);
+        auto settings = Tests::TServerSettings(mbusport)
+            .SetDomainName("Root")
+            .SetUseRealThreads(false);
+
+        Tests::TServer::TPtr server = new Tests::TServer(settings);
+
+        auto runtime = server->GetRuntime();
+        auto sender = runtime->AllocateEdgeActor();
+        auto kqpProxy = MakeKqpProxyID(runtime->GetNodeId(0));
+
+        InitRoot(server, sender);
+
+        auto createSession = [&]() {
+            runtime->Send(new IEventHandle(kqpProxy, sender, new TEvKqp::TEvCreateSessionRequest()));
+            auto reply = runtime->GrabEdgeEventRethrow<TEvKqp::TEvCreateSessionResponse>(sender);
+            auto record = reply->Get()->Record;
+            UNIT_ASSERT_VALUES_EQUAL(record.GetYdbStatus(), Ydb::StatusIds::SUCCESS);
+            return record.GetResponse().GetSessionId();
+        };
+
+        auto sendQuery = [&](const TString& queryText) {
+            auto ev = std::make_unique<NKqp::TEvKqp::TEvQueryRequest>();
+            ev->Record.MutableRequest()->SetAction(NKikimrKqp::QUERY_ACTION_EXPLAIN);
+            ev->Record.MutableRequest()->SetType(NKikimrKqp::QUERY_TYPE_SQL_GENERIC_QUERY);
+            ev->Record.MutableRequest()->SetQuery(queryText);
+            ev->Record.MutableRequest()->SetSyntax(::Ydb::Query::Syntax::SYNTAX_PG);
+            ev->Record.MutableRequest()->SetKeepSession(false);
+            ActorIdToProto(sender, ev->Record.MutableRequestActorId());
+
+            runtime->Send(new IEventHandle(kqpProxy, sender, ev.release()));
+            return runtime->GrabEdgeEventRethrow<TEvKqp::TEvQueryResponse>(sender);
+        };
+
+        createSession();
+
+        auto reply = sendQuery(R"(
+            SELECT 2 y, 1 x;
+        )");
+
+        UNIT_ASSERT_VALUES_EQUAL(reply->Get()->Record.GetRef().GetYdbStatus(), Ydb::StatusIds::SUCCESS);
+        UNIT_ASSERT_VALUES_EQUAL(reply->Get()->Record.GetRef().GetResponse().GetYdbResults().size(), 1);
+        Cerr << reply->Get()->Record.GetRef().GetResponse().DebugString() << Endl;
+        auto ydbResults = reply->Get()->Record.GetRef().GetResponse().GetYdbResults();
+        TVector <TString> colNames = {"y", "x"};
+        UNIT_ASSERT_VALUES_EQUAL(colNames.size(), ydbResults.begin()->Getcolumns().size());
+        for (size_t i = 0; i < colNames.size(); i++) {
+            UNIT_ASSERT_VALUES_EQUAL(ydbResults.begin()->Getcolumns().at(i).Getname(), colNames[i]);
+        }
+   }
 }
 
 } // namespace NKqp