test: add testcases comparing NULL with NULL

project-tsurugi · Feb 13, 2025 · 5fa0316 · 5fa0316
1 parent 2740e9a
commit 5fa0316
Showing 1 changed file with 49 additions and 0 deletions.
diff --git a/test/jogasaki/api/sql_test.cpp b/test/jogasaki/api/sql_test.cpp
@@ -647,8 +647,57 @@ TEST_F(sql_test, nullif_expression) {
         EXPECT_EQ((create_nullable_record<kind::int4>(1)), result[0]);
         EXPECT_EQ((create_nullable_record<kind::int4>(2)), result[1]);
     }
+    {
+        // it's possible to compare null with null - compiler once made it as an error
+        std::vector<mock::basic_record> result{};
+        execute_query("select nullif(null, null) from t0", result);
+        ASSERT_EQ(2, result.size());
+        std::sort(result.begin(), result.end());
+        EXPECT_EQ((create_nullable_record<kind::unknown>(-1, {true})), result[0]);
+        EXPECT_EQ((create_nullable_record<kind::unknown>(-1, {true})), result[1]);
+    }
 }
 
+TEST_F(sql_test, null_comparison_by_operator) {
+    // compare literal-like NULL with itself - once compiler made it as an error
+    execute_statement("create table t0 (c0 int)");
+    execute_statement("INSERT INTO t0 VALUES (1), (NULL)");
+    {
+        std::vector<mock::basic_record> result{};
+        execute_query("select * from t0 where NULL = NULL", result);
+        ASSERT_EQ(0, result.size());
+    }
+    {
+        std::vector<mock::basic_record> result{};
+        execute_query("select * from t0 where NULL <> NULL", result);
+        ASSERT_EQ(0, result.size());
+    }
+    {
+        std::vector<mock::basic_record> result{};
+        execute_query("select * from t0 where c0 = NULL", result);
+        ASSERT_EQ(0, result.size());
+    }
+    {
+        std::vector<mock::basic_record> result{};
+        execute_query("select * from t0 where c0 <> NULL", result);
+        ASSERT_EQ(0, result.size());
+    }
+    {
+        std::vector<mock::basic_record> result{};
+        execute_query("select * from t0 where NULL IS NULL", result);
+        ASSERT_EQ(2, result.size());
+        std::sort(result.begin(), result.end());
+        EXPECT_EQ((create_nullable_record<kind::int4>(-1, {true})), result[0]);
+        EXPECT_EQ((create_nullable_record<kind::int4>(1)), result[1]);
+    }
+    {
+        std::vector<mock::basic_record> result{};
+        execute_query("select * from t0 where NULL IS NOT NULL", result);
+        ASSERT_EQ(0, result.size());
+    }
+}
+
+
 TEST_F(sql_test, type_of_cast_conversion) {
     // verify the result type of cast - issue #982
     // TODO currently comparison with basic_record does not distinguish triples of same value with different representation