Question

使用下面的类和底部的测试程序，我得到格式错误的Insert，其中Application_Id的值写为＆＃39;（n，）＆＃39;，其中＆＃39; n＆＃39; s已插入的值，即如果Application_Id应为2，则值＆＃39;（2，＆＃39;）就在其中。

我无法找到原因，因为据我所知，其他外键列的处理方式没有区别。（排除所有进口 - 这不是问题）。

我在Windows 10 + Visual Studio 2015上使用Python 3.4.4和SQLAlchemy 1.1.5。切换到另一个操作系统或IDE不是一个选项： - （

时间跨度

class Timespan(Base):
    """

    """
    __tablename__ = 'timespan'
    def __init__(self, start, end, account, application, language):
        self.StartTime = start
        self.EndTime = end
        self.Account_Id = account
        self.Application_Id = application,
        self.Language_Id = language

    StartTime = Column(DateTime)
    EndTime = Column(DateTime)
    Id = Column(Integer, primary_key = True)
    Account_Id = Column(Integer, ForeignKey('account.Id'))
    Application_Id = Column(Integer, ForeignKey('application.Id'))
    Language_Id = Column(Integer, ForeignKey('language.Id'))

应用

class Application(Base):
    """

    """
    __tablename__ = 'application'
    Id = Column(Integer, primary_key = True)
    Code = Column(String)
    Description = Column(String)

    def __init__(self, code, description):
        self.Code = code
        self.Description = description

帐户

class Account(Base):
    """

    """

    __tablename__ = 'account'

    def __init__(self, uid, domain):
        self.MvidDomain = domain
        self.MvidUid = uid

    Id = Column(Integer, primary_key = True)
    MvidUid = Column(Integer)
    MvidDomain = Column(String)

语言

class Language(Base):
    """

    """
    def __init__(self, description, code):
        self.Description = description
        self.Code = code

    __tablename__ = 'language'

    Id = Column(Integer, primary_key = True)
    Description = Column(String)
    Code = Column(String)

测试程序

class TimespanTest(TestCase):
    def test_insert(self):
        engine = create_engine('sqlite://', echo = True)
        Base.metadata.create_all(engine)

        Session = sessionmaker(bind = engine)
        session = Session()
        application = Application(code = 'itw', description = 'desc')
        lang = Language(description = 'test language', code = 'da')
        account = Account(uid = 'test_user', domain = 'test_domain')

        session.add(lang)
        session.add(application)
        session.add(account)
        session.commit()

        print (lang.Id)
        print (application.Id)
        print (account.Id)

        timespan = Timespan(
                datetime.today(), datetime.today(),
                account = account.Id,
                application = application.Id,
                language = lang.Id)
        session.add(timespan)
        session.commit()

调试输出/例外：

(sqlite3.InterfaceError) Error binding parameter 3 - probably unsupported type. 
[SQL: 'INSERT INTO timespan ("StartTime", "EndTime", "Account_Id", "Application_Id", "Language_Id") VALUES (?, ?, ?, ?, ?)']
[parameters: ('2017-01-24 08:29:23.447994', '2017-01-24 08:29:23.447994', 1, (1,), 1)]

问题出现在倒数第二个参数中，即值（1，），它应该只是1。

Answer 1

Timespan 类中存在问题，请注意 = 后，，删除此项并继续工作。以下代码删除了逗号： -

class Timespan(Base):
    """

    """
    __tablename__ = 'timespan'
    def __init__(self, start, end, account, application, language):
        self.StartTime = start
        self.EndTime = end
        self.Account_Id = account
        self.Application_Id = application
        self.Language_Id = language

    StartTime = Column(DateTime)
    EndTime = Column(DateTime)
    Id = Column(Integer, primary_key = True)
    Account_Id = Column(Integer, ForeignKey('account.Id'))
    Application_Id = Column(Integer, ForeignKey('application.Id'))
    Language_Id = Column(Integer, ForeignKey('language.Id'))

为什么SQLAlchemy会生成具有不正确值的插入

1 个答案: