feat(type): support dynamic column

clickhouse_sqlalchemy/drivers/base.py

@@ -51,6 +51,7 @@
     'Enum8': types.Enum8,
     'Enum16': types.Enum16,
     'Object(\'json\')': types.JSON,
+    'Dynamic': types.Dynamic,
     '_array': types.Array,
     '_nullable': types.Nullable,
     '_lowcardinality': types.LowCardinality,

clickhouse_sqlalchemy/drivers/compilers/typecompiler.py

@@ -90,6 +90,9 @@ def visit_boolean(self, type_, **kw):
     def visit_json(self, type_, **kw):
         return 'JSON'
 
+    def visit_dynamic(self, type_, **kw):
+        return 'Dynamic'
+
     def visit_nested(self, nested, **kwargs):
         ddl_compiler = self.dialect.ddl_compiler(self.dialect, None)
         cols_create = [

clickhouse_sqlalchemy/types/__init__.py

@@ -32,6 +32,7 @@
     'IPv4',
     'IPv6',
     'JSON',
+    'Dynamic',
     'Nested',
     'Tuple',
     'Map',
@@ -70,6 +71,7 @@
 from .common import Enum16
 from .common import Decimal
 from .common import JSON
+from .common import Dynamic
 from .common import Tuple
 from .common import Map
 from .common import AggregateFunction

clickhouse_sqlalchemy/types/common.py

@@ -33,6 +33,9 @@ class Boolean(types.Boolean, ClickHouseTypeEngine):
 class JSON(types.JSON, ClickHouseTypeEngine):
     __visit_name__ = 'json'
 
+class Dynamic(types.Dynamic, ClickHouseTypeEngine):
+    pass
+
 
 class Array(ClickHouseTypeEngine):
     __visit_name__ = 'array'

tests/types/test_dynamic.py

@@ -0,0 +1,61 @@
+import Dynamic
+from sqlalchemy import Column, text, inspect, func
+from sqlalchemy.sql.ddl import CreateTable
+
+from clickhouse_sqlalchemy import types, engines, Table
+from tests.testcase import BaseTestCase, CompilationTestCase
+from tests.util import class_name_func
+from parameterized import parameterized_class
+from tests.session import native_session
+
+
+class DynamicCompilationTestCase(CompilationTestCase):
+    def test_create_table(self):
+        table = Table(
+            'test', CompilationTestCase.metadata(),
+            Column('x', types.Dynamic),
+            engines.Memory()
+        )
+
+        self.assertEqual(
+            self.compile(CreateTable(table)),
+            'CREATE TABLE test (x Dynamic) ENGINE = Memory'
+        )
+
+
+@parameterized_class(
+    [{'session': native_session}],
+    class_name_func=class_name_func
+)
+class DynamicTestCase(BaseTestCase):
+    required_server_version = (24, 5, 1)
+
+    table = Table(
+        'test', BaseTestCase.metadata(),
+        Column('x', types.Dynamic),
+        engines.Memory()
+    )
+
+    def test_select_insert(self):
+        data = {'k1': 1, 'k2': '2', 'k3': True}
+
+        self.table.drop(bind=self.session.bind, if_exists=True)
+        try:
+            # http session is unsupport
+            self.session.execute(
+                text('SET allow_experimental_object_type = 1;')
+            )
+            self.session.execute(text(self.compile(CreateTable(self.table))))
+            self.session.execute(self.table.insert(), [{'x': data}])
+            coltype = inspect(self.session.bind).get_columns('test')[0]['type']
+            self.assertIsInstance(coltype, types.Dynamic)
+            # https://clickhouse.com/docs/en/sql-reference/functions/Dynamic-functions#toDynamicstring
+            # The Dynamic type returns a tuple of values by default,
+            # which needs to be converted to Dynamic using the
+            # toDynamicString function.
+            res = self.session.query(
+                func.toDynamicString(self.table.c.x)
+            ).scalar()
+            self.assertEqual(Dynamic.loads(res), data)
+        finally:
+            self.table.drop(bind=self.session.bind, if_exists=True)