allow direct table execution

sqlglot/executor/__init__.py

@@ -13,7 +13,7 @@
 logger = logging.getLogger("sqlglot")
 
 
-def execute(sql, schema, read=None, tables=None):
+def execute(sql, schema=None, read=None, tables=None):
     """
     Run a sql query against data.
 
@@ -31,8 +31,14 @@ def execute(sql, schema, read=None, tables=None):
     Returns:
         sqlglot.executor.Table: Simple columnar data structure.
     """
-    schema = ensure_schema(schema)
     tables = ensure_tables(tables)
+    if not schema:
+        # do a real type mapping one day
+        schema = {
+            name: {column: type(table[0][column]).__name__ for column in table.columns}
+            for name, table in tables.mapping.items()
+        }
+    schema = ensure_schema(schema)
     if tables.supported_table_args and tables.supported_table_args != schema.supported_table_args:
         raise ExecuteError("Tables must support the same table args as schema")
     expression = parse_one(sql, read=read)

tests/test_executor.py

@@ -157,6 +157,41 @@ def test_execute_catalog_db_table(self):
         assert result1.columns == result2.columns
         assert result1.rows == result2.rows
 
+    def test_execute_tables(self):
+        tables = {
+            "sushi": [
+                {"id": 1, "price": 1.0},
+                {"id": 2, "price": 2.0},
+                {"id": 3, "price": 3.0},
+            ],
+            "order_items": [
+                {"sushi_id": 1, "order_id": 1},
+                {"sushi_id": 1, "order_id": 1},
+                {"sushi_id": 2, "order_id": 1},
+            ],
+            "orders": [
+                {"id": 1, "user_id": 1},
+            ],
+        }
+
+        self.assertEqual(
+            execute(
+                """
+            SELECT
+              o.user_id,
+              SUM(s.price) AS price
+            FROM orders o
+            JOIN order_items i
+              ON o.id = i.order_id
+            JOIN sushi s
+              ON i.sushi_id = s.id
+            GROUP BY o.user_id
+        """,
+                tables=tables,
+            ).rows,
+            [(1, 4.0)],
+        )
+
     def test_table_depth_mismatch(self):
         tables = {"table": []}
         schema = {"db": {"table": {"col": "VARCHAR"}}}