Add logic to escape Map data type to support insert statements. (#266)

* Add logic to escape Map data type to support insert statements.

clickhouse_sqlalchemy/drivers/http/escaper.py

@@ -66,6 +66,13 @@ def escape_item(self, item):
             return "[" + ", ".join(
                 [str(self.escape_item(x)) for x in item]
             ) + "]"
+        elif isinstance(item, dict):
+            return "{" + ", ".join(
+                ["{}: {}".format(
+                    self.escape_item(k),
+                    self.escape_item(v)
+                ) for k, v in item.items()]
+            ) + "}"
         elif isinstance(item, enum.Enum):
             return self.escape_string(item.name)
         else:

tests/drivers/http/test_escaping.py

@@ -28,7 +28,7 @@ def test_escaper(self):
         self.assertEqual(e.escape([Decimal('10')]), '[10.0]')
         self.assertEqual(e.escape([10.0]), '[10.0]')
         self.assertEqual(e.escape([date(2017, 1, 2)]), "['2017-01-02']")
-
+        self.assertEqual(e.escape(dict(x=10, y=20)), {'x': 10, 'y': 20})
         with self.assertRaises(Exception) as ex:
             e.escape([object()])
 

tests/sql/test_insert.py

@@ -20,3 +20,22 @@ def test_insert(self):
 
             rv = self.session.execute(select(table.c.x)).scalar()
             self.assertEqual(rv, 'test')
+
+    @require_server_version(21, 1, 3)
+    def test_insert_map(self):
+        table = Table(
+            't', self.metadata(),
+            Column('x', types.Map(types.String, types.Int32),
+                   primary_key=True),
+            engines.Memory()
+        )
+
+        with self.create_table(table):
+            dict_map = dict(key1=1, Key2=2)
+            x = [
+                {'x': dict_map}
+            ]
+            self.session.execute(table.insert(), x)
+
+            rv = self.session.execute(select(table.c.x)).scalar()
+            self.assertEqual(rv, dict_map)