Add duckdb support (#7548)

tests/query_runner/test_duckdb.py

@@ -0,0 +1,107 @@
+from unittest import TestCase
+from unittest.mock import patch
+
+from redash.query_runner.duckdb import DuckDB
+
+
+class TestDuckDBSchema(TestCase):
+    def setUp(self) -> None:
+        self.runner = DuckDB({"dbpath": ":memory:"})
+
+    @patch.object(DuckDB, "run_query")
+    def test_simple_schema_build(self, mock_run_query) -> None:
+        # Simulate queries: first for tables, then for DESCRIBE
+        mock_run_query.side_effect = [
+            (
+                {"rows": [{"table_schema": "main", "table_name": "users"}]},
+                None,
+            ),
+            (
+                {
+                    "rows": [
+                        {"column_name": "id", "column_type": "INTEGER"},
+                        {"column_name": "name", "column_type": "VARCHAR"},
+                    ]
+                },
+                None,
+            ),
+        ]
+
+        schema = self.runner.get_schema()
+        self.assertEqual(len(schema), 1)
+        self.assertEqual(schema[0]["name"], "main.users")
+        self.assertListEqual(
+            schema[0]["columns"],
+            [{"name": "id", "type": "INTEGER"}, {"name": "name", "type": "VARCHAR"}],
+        )
+
+    @patch.object(DuckDB, "run_query")
+    def test_struct_column_expansion(self, mock_run_query) -> None:
+        # First call to run_query -> tables list
+        mock_run_query.side_effect = [
+            (
+                {"rows": [{"table_schema": "main", "table_name": "events"}]},
+                None,
+            ),
+            # Second call -> DESCRIBE output
+            (
+                {
+                    "rows": [
+                        {
+                            "column_name": "payload",
+                            "column_type": "STRUCT(a INTEGER, b VARCHAR)",
+                        }
+                    ]
+                },
+                None,
+            ),
+        ]
+
+        schema_list = self.runner.get_schema()
+        self.assertEqual(len(schema_list), 1)
+        schema = schema_list[0]
+
+        # Ensure both raw and expanded struct fields are present
+        self.assertIn("main.events", schema["name"])
+        self.assertListEqual(
+            schema["columns"],
+            [
+                {"name": "payload", "type": "STRUCT(a INTEGER, b VARCHAR)"},
+                {"name": "payload.a", "type": "INTEGER"},
+                {"name": "payload.b", "type": "VARCHAR"},
+            ],
+        )
+
+    def test_nested_struct_expansion(self) -> None:
+        runner = DuckDB({"dbpath": ":memory:"})
+        runner.con.execute(
+            """
+            CREATE TABLE sample_struct_table (
+                id INTEGER,
+                info STRUCT(
+                    name VARCHAR,
+                    metrics STRUCT(score DOUBLE, rank INTEGER),
+                    tags STRUCT(primary_tag VARCHAR, secondary_tag VARCHAR)
+                )
+            );
+        """
+        )
+
+        schema = runner.get_schema()
+        table = next(t for t in schema if t["name"] == "main.sample_struct_table")
+        colnames = [c["name"] for c in table["columns"]]
+
+        assert "info" in colnames
+        assert 'info."name"' in colnames
+        assert "info.metrics" in colnames
+        assert "info.metrics.score" in colnames
+        assert "info.metrics.rank" in colnames
+        assert "info.tags.primary_tag" in colnames
+        assert "info.tags.secondary_tag" in colnames
+
+    @patch.object(DuckDB, "run_query")
+    def test_error_propagation(self, mock_run_query) -> None:
+        mock_run_query.return_value = (None, "boom")
+        with self.assertRaises(Exception) as ctx:
+            self.runner.get_schema()
+        self.assertIn("boom", str(ctx.exception))