Python SQL Alchemy无事务开始错误
我运行以下代码Python SQL Alchemy无事务开始错误,python,sqlalchemy,Python,Sqlalchemy,我运行以下代码 db = create_engine('sqlite:///tracking_test.db') db.echo= True metadata = MetaData(db) session = create_session(bind=db) #define tables, if they exist sqlalchemly will find them and sycn otherwise they will be created delivered= Table('delive
db = create_engine('sqlite:///tracking_test.db')
db.echo= True
metadata = MetaData(db)
session = create_session(bind=db)
#define tables, if they exist sqlalchemly will find them and sycn otherwise they will be created
delivered= Table('delivered', metadata,
Column('delivered_id',Integer,primary_key=True),
Column('domain',String(200)),
Column('path',String(500)),
)
class Delivered(object):
def __init__(self,obj):
self.domain=u'%s' % obj.get("dm","")
self.path=u'%s' % obj.get("pth","")
report1t = Table('clicked', metadata,
Column('clicked_id',Integer,primary_key=True),
Column('domain',String(200)),
Column('path',String(500)),
)
class report1(object):
def __init__(self,obj):
self.domain=u'%s' % obj.get("dm","")
self.path=u'%s' % obj.get("pth","")
metadata.create_all()
mapper(report1, report1t)
mapper(Delivered,delivered)
result= {}#some dict
newT = Delivered(result)
if newT:
session.add(newT)
session.commit()
session.flush()
我得到了这个错误
sqlalchemy.exc.InvalidRequestError:未开始任何事务
会议内容如下:
{'autocommit': True, 'autoflush': False, 'transaction': None, 'hash_key': 4317750544, 'expire_on_commit': False, '_new': {<sqlalchemy.orm.state.InstanceState object at 0x101a79ad0>: <__main__.adDelivered object at 0x101a799d0>}, 'bind': Engine(sqlite:///adtracking_test.db), '_deleted': {}, '_flushing': False, 'identity_map': {}, 'dispatch': <sqlalchemy.event.SessionEventsDispatch object at 0x101a82f90>, '_enable_transaction_accounting': True, '_identity_cls': <class 'sqlalchemy.orm.identity.WeakInstanceDict'>, 'twophase': False, '_Session__binds': {}, '_query_cls': <class 'sqlalchemy.orm.query.Query'>}
{'autocommit':True,'autoflush':False,'transaction':None,'hash_key':4317750544,'expire_on_commit':False,'u new':{:},'bind':引擎(sqlite:///adtracking_test.db),“'u deleted':{},'u flushing':False,'identity\u map':{},'dispatch':,'u enable\u transaction\u accounting':True,'u identity\u cls':,'twophase':False,'u Session\u binds':{},“\u query\u cls”:
有人知道我做错了什么吗
谢谢,
CG如果您发布完整的回溯,将非常有用。但是,我认为问题在于创建会话的方式。我认为您应该使用
sessionmaker
而不是create\u session
(我以前从未见过该函数,也没有在任何地方看到它的文档)sessionmaker
创建一个新的Session
类,您需要实例化它。因此:
Session = sessionmaker(bind=db)
session = Session()
...
session.add(newT)
执行以下代码行中提到的提交时,出现类似错误“未开始任何事务”:
db_session = scoped_session(sessionmaker(autocommit=False, autoflush=False, bind=engine))
db_session.add(target)
db_session.commit()
在我的例子中,由于我将autocommit设置为True并尝试提交(),所以发生了错误。为解决此问题,已将自动提交设置为False,如下面的代码所示
db_session = scoped_session(sessionmaker(autocommit=False, autoflush=False, bind=engine))
谢谢,
Karthik这似乎起到了作用,我不确定我在哪里找到了createsession。