From 650b899a0e8e7a4eb67a48358ba33660eba095de Mon Sep 17 00:00:00 2001
From: Anshul Data <anshul@sundeck.io>
Date: Thu, 14 Nov 2024 10:12:55 +0530
Subject: [PATCH] feat: Add support for to_substrait for virtual table
 expression

---
 src/include/to_substrait.hpp    |  1 +
 src/to_substrait.cpp            | 21 +++++++++++++++++++++
 test/c/test_substrait_c_api.cpp | 21 +++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/src/include/to_substrait.hpp b/src/include/to_substrait.hpp
index aa063b8..30db7ed 100644
--- a/src/include/to_substrait.hpp
+++ b/src/include/to_substrait.hpp
@@ -59,6 +59,7 @@ class DuckDBToSubstrait {
 	substrait::Rel *TransformOrderBy(LogicalOperator &dop);
 	substrait::Rel *TransformComparisonJoin(LogicalOperator &dop);
 	substrait::Rel *TransformAggregateGroup(LogicalOperator &dop);
+	substrait::Rel *TransformExpressionGet(LogicalOperator &dop);
 	substrait::Rel *TransformGet(LogicalOperator &dop);
 	substrait::Rel *TransformCrossProduct(LogicalOperator &dop);
 	substrait::Rel *TransformUnion(LogicalOperator &dop);
diff --git a/src/to_substrait.cpp b/src/to_substrait.cpp
index 5fb7f2b..53c97c6 100644
--- a/src/to_substrait.cpp
+++ b/src/to_substrait.cpp
@@ -1339,6 +1339,25 @@ substrait::Rel *DuckDBToSubstrait::TransformGet(LogicalOperator &dop) {
 	return get_rel;
 }
 
+substrait::Rel *DuckDBToSubstrait::TransformExpressionGet(LogicalOperator &dop) {
+	auto get_rel = new substrait::Rel();
+	auto &dget = dop.Cast<LogicalExpressionGet>();
+
+	auto sget = get_rel->mutable_read();
+	auto virtual_table = sget->mutable_virtual_table();
+
+	for (auto &row : dget.expressions) {
+		auto row_item = virtual_table->add_expressions();
+		for (auto &expr : row) {
+			auto s_expr = new substrait::Expression();
+			TransformExpr(*expr, *s_expr);
+			*row_item->add_fields() = *s_expr;
+			delete s_expr;
+		}
+	}
+	return get_rel;
+}
+
 substrait::Rel *DuckDBToSubstrait::TransformCrossProduct(LogicalOperator &dop) {
 	auto rel = new substrait::Rel();
 	auto sub_cross_prod = rel->mutable_cross();
@@ -1435,6 +1454,8 @@ substrait::Rel *DuckDBToSubstrait::TransformOp(LogicalOperator &dop) {
 		return TransformAggregateGroup(dop);
 	case LogicalOperatorType::LOGICAL_GET:
 		return TransformGet(dop);
+	case LogicalOperatorType::LOGICAL_EXPRESSION_GET:
+		return TransformExpressionGet(dop);
 	case LogicalOperatorType::LOGICAL_CROSS_PRODUCT:
 		return TransformCrossProduct(dop);
 	case LogicalOperatorType::LOGICAL_UNION:
diff --git a/test/c/test_substrait_c_api.cpp b/test/c/test_substrait_c_api.cpp
index fe79d65..6307bf1 100644
--- a/test/c/test_substrait_c_api.cpp
+++ b/test/c/test_substrait_c_api.cpp
@@ -4,6 +4,7 @@
 
 #include <chrono>
 #include <thread>
+#include <iostream>
 
 using namespace duckdb;
 using namespace std;
@@ -45,3 +46,23 @@ TEST_CASE("Test C Get and To Json-Substrait API", "[substrait-api]") {
 
   REQUIRE_THROWS(con.FromSubstraitJSON("this is not valid"));
 }
+
+
+TEST_CASE("Test C VirtualTable input Literal", "[substrait-api]") {
+  DuckDB db(nullptr);
+  Connection con(db);
+
+  auto json = con.GetSubstraitJSON("select * from (values (1, 2),(3, 4))");
+  REQUIRE(!json.empty());
+  std::cout << json << std::endl;
+}
+
+TEST_CASE("Test C VirtualTable input Expression", "[substrait-api]") {
+  DuckDB db(nullptr);
+  Connection con(db);
+
+  auto json = con.GetSubstraitJSON("select * from (values (1+1,2+2),(3+3,4+4)) as temp(a,b)");
+  REQUIRE(!json.empty());
+  std::cout << json << std::endl;
+
+}