text: from __future__ import unicode_literals, print_function
  
  import unittest
  import json
  
  from infi.clickhouse_orm import database, engines, fields, models
  
  
  class JoinTest(unittest.TestCase):
  
      def setUp(self):
          self.database = database.Database('test-db', log_statements=True)
          self.database.create_table(Foo)
          self.database.create_table(Bar)
          self.database.insert([Foo(id=i) for i in range(3)])
          self.database.insert([Bar(id=i, b=i * i) for i in range(3)])
  
      def print_res(self, query):
          print(query)
          print(json.dumps([row.to_dict() for row in self.database.select(query)]))
  
      def test_without_db_name(self):
          self.print_res("SELECT * FROM {}".format(Foo.table_name()))
          self.print_res("SELECT * FROM {}".format(Bar.table_name()))
          self.print_res("SELECT b FROM {} ALL LEFT JOIN {} USING id".format(Foo.table_name(), Bar.table_name()))
  
      def test_with_db_name(self):
          self.print_res("SELECT * FROM $db.{}".format(Foo.table_name()))
          self.print_res("SELECT * FROM $db.{}".format(Bar.table_name()))
          self.print_res("SELECT b FROM $db.{} ALL LEFT JOIN $db.{} USING id".format(Foo.table_name(), Bar.table_name()))
  
      def test_with_subquery(self):
          self.print_res("SELECT b FROM {} ALL LEFT JOIN (SELECT * from {}) subquery USING id".format(Foo.table_name(), Bar.table_name()))
          self.print_res("SELECT b FROM $db.{} ALL LEFT JOIN (SELECT * from $db.{}) subquery USING id".format(Foo.table_name(), Bar.table_name()))
  
  
  class Foo(models.Model):
      id = fields.UInt8Field()
      engine = engines.Memory()
  
  
  class Bar(Foo):
      b = fields.UInt8Field()
  