SQLAlchemy bulk_save_objects无法保存具有版本控制字段的更新对象

Question

我试图在我的行上使用版本控制的组合，并且bulk_save_objects。这是我的代码，当我尝试在代码的最后给函数一个更新的对象时，它失败。

import datetime 
import sqlalchemy as sqa 
import sqlalchemy.ext 
import sqlalchemy.ext.declarative 
import sqlalchemy.orm 

Base = sqa.ext.declarative.declarative_base() 
class Test(Base): 
    __tablename__ = 'gads_sqlalchemyTest' 

    id = sqa.Column(sqa.Integer, primary_key = True) 
    id2 = sqa.Column(sqa.String(50), primary_key = True) 
    name = sqa.Column(sqa.String(200)) 
    lastUpdated = sqa.Column(sqa.DateTime) 

    __mapper_args__ = { 
     'version_id_col': lastUpdated, 
     'version_id_generator': lambda version: datetime.datetime.now() 
    } 

    def __repr__(self): 
     return('<Test(id: %d, name: %s)>' % (
      self.id, self.name)) 


if __name__ == '__main__': 
    connection_string = ('mssql+pyodbc://' 
         'username:password@server:1433/' 
         'databasename' 
         '?driver=FreeTDS') 
    engine = sqa.create_engine(connection_string, echo=True) 

    Base.metadata.create_all(engine) 
    Session = sqa.orm.sessionmaker(bind = engine) 
    session = Session() 

    objects = [] 
    for i in range(3): 
     tmp = Test() 
     tmp.id = i 
     tmp.id2 = 'SE' 
     tmp.name = 'name %d' % i 
     objects.append(tmp) 

    session.bulk_save_objects(objects) 
    session.commit() 

    tmp = session.query(Test).filter(Test.id == 1).one() 
    tmp.name = 'test' 
    session.bulk_save_objects([tmp]) 
    session.commit() 

而这里的输出：

2016-08-16 09:44:00,710 INFO sqlalchemy.engine.base.Engine 
      SELECT default_schema_name FROM 
      sys.database_principals 
      WHERE principal_id=database_principal_id() 

2016-08-16 09:44:00,710 INFO sqlalchemy.engine.base.Engine() 
2016-08-16 09:44:00,729 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS VARCHAR(60)) AS anon_1 
2016-08-16 09:44:00,729 INFO sqlalchemy.engine.base.Engine() 
2016-08-16 09:44:00,734 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS NVARCHAR(60)) AS anon_1 
2016-08-16 09:44:00,734 INFO sqlalchemy.engine.base.Engine() 
2016-08-16 09:44:00,740 INFO sqlalchemy.engine.base.Engine SELECT [INFORMATION_SCHEMA].[COLUMNS].[TABLE_SCHEMA], [INFORMATION_SCHEMA].[COLUMNS].[TABLE_NAME], [INFORMATION_SCHEMA].[COLUMNS].[COLUMN_NAME], [INFORMATION_SCHEMA].[COLUMNS].[IS_NULLABLE], [INFORMATION_SCHEMA].[COLUMNS].[DATA_TYPE], [INFORMATION_SCHEMA].[COLUMNS].[ORDINAL_POSITION], [INFORMATION_SCHEMA].[COLUMNS].[CHARACTER_MAXIMUM_LENGTH], [INFORMATION_SCHEMA].[COLUMNS].[NUMERIC_PRECISION], [INFORMATION_SCHEMA].[COLUMNS].[NUMERIC_SCALE], [INFORMATION_SCHEMA].[COLUMNS].[COLUMN_DEFAULT], [INFORMATION_SCHEMA].[COLUMNS].[COLLATION_NAME] 
FROM [INFORMATION_SCHEMA].[COLUMNS] 
WHERE [INFORMATION_SCHEMA].[COLUMNS].[TABLE_NAME] = CAST(? AS NVARCHAR(max)) AND [INFORMATION_SCHEMA].[COLUMNS].[TABLE_SCHEMA] = CAST(? AS NVARCHAR(max)) 
2016-08-16 09:44:00,741 INFO sqlalchemy.engine.base.Engine ('gads_sqlalchemyTest', 'dbo') 
2016-08-16 09:44:00,966 INFO sqlalchemy.engine.base.Engine BEGIN (implicit) 
2016-08-16 09:44:00,967 INFO sqlalchemy.engine.base.Engine INSERT INTO [gads_sqlalchemyTest] (id, id2, name, [lastUpdated]) VALUES (?, ?, ?, ?) 
2016-08-16 09:44:00,968 INFO sqlalchemy.engine.base.Engine ((0, 'SE', 'as;dkljasdfl;kj 0 1', datetime.datetime(2016, 8, 16, 9, 44, 0, 967306)), (1, 'SE', 'as;dkljasdfl;kj 1 2', datetime.datetime(2016, 8, 16, 9, 44, 0, 967328)), (2, 'SE', 'as;dkljasdfl;kj 2 3', datetime.datetime(2016, 8, 16, 9, 44, 0, 967337))) 
2016-08-16 09:44:00,976 INFO sqlalchemy.engine.base.Engine COMMIT 
2016-08-16 09:44:00,984 INFO sqlalchemy.engine.base.Engine BEGIN (implicit) 
2016-08-16 09:44:00,986 INFO sqlalchemy.engine.base.Engine SELECT [gads_sqlalchemyTest].id AS [gads_sqlalchemyTest_id], [gads_sqlalchemyTest].id2 AS [gads_sqlalchemyTest_id2], [gads_sqlalchemyTest].name AS [gads_sqlalchemyTest_name], [gads_sqlalchemyTest].[lastUpdated] AS [gads_sqlalchemyTest_lastUpdated] 
FROM [gads_sqlalchemyTest] 
WHERE [gads_sqlalchemyTest].id = ? 
2016-08-16 09:44:00,986 INFO sqlalchemy.engine.base.Engine (1,) 
2016-08-16 09:44:00,992 INFO sqlalchemy.engine.base.Engine ROLLBACK 
Traceback (most recent call last): 
    File "tmp.py", line 60, in <module> 
    session.bulk_save_objects([tmp]) 
    File "/home/adrin/Projects/venv/lib/python3.5/site-packages/sqlalchemy/orm/session.py", line 2264, in bulk_save_objects 
    return_defaults, update_changed_only, False) 
    File "/home/adrin/Projects/venv/lib/python3.5/site-packages/sqlalchemy/orm/session.py", line 2428, in _bulk_save_mappings 
    transaction.rollback(_capture_exception=True) 
    File "/home/adrin/Projects/venv/lib/python3.5/site-packages/sqlalchemy/util/langhelpers.py", line 60, in __exit__ 
    compat.reraise(exc_type, exc_value, exc_tb) 
    File "/home/adrin/Projects/venv/lib/python3.5/site-packages/sqlalchemy/util/compat.py", line 186, in reraise 
    raise value 
    File "/home/adrin/Projects/venv/lib/python3.5/site-packages/sqlalchemy/orm/session.py", line 2419, in _bulk_save_mappings 
    isstates, update_changed_only) 
    File "/home/adrin/Projects/venv/lib/python3.5/site-packages/sqlalchemy/orm/persistence.py", line 123, in _bulk_update 
    bookkeeping=False) 
    File "/home/adrin/Projects/venv/lib/python3.5/site-packages/sqlalchemy/orm/persistence.py", line 642, in _emit_update_statements 
    lambda rec: (
    File "/home/adrin/Projects/venv/lib/python3.5/site-packages/sqlalchemy/orm/persistence.py", line 439, in _collect_update_commands 
    update_version_id in states_to_update: 
    File "/home/adrin/Projects/venv/lib/python3.5/site-packages/sqlalchemy/orm/persistence.py", line 117, in <genexpr> 
    for mapping in mappings 
KeyError: 'lastUpdated' 

的代码运行平稳，如果我只是完全删除lastUpdated领域。

编辑： 有修正错误here

Answer 1

批量操作速度的名义绕过了很多的SQLAlchemy的功能的补丁。每个批量操作在文档中都有大量的警告和注意事项。如果版本控制功能是绕过的其中一项，我不会感到惊讶。