修改SQLAlchemy对象中的现有值

Mike Wild 发表于 Dev

迈克·怀尔德

我正在尝试在检索的SQLAlchemy对象中使用现有字符串，并将其与第二个字符串连接起来，但是没有值被写入。

print(messages)
testsuite = session.query(Testsuite).get(test_id)
testsuite.console += messages
session.commit()

检查数据库时，记录保持其原始空值-messages从未添加。

我的Testsuite模型如下：

# Represents schema - used by engine to create tables etc.
Base = declarative_base()


# These SQL fields are horrendously inefficient - need replacing ASAP!
class Testsuite(Base):
    """Testsuite model to map testsuite in progress to SQL DB."""

    __tablename__ = 'testsuites'

    id = Column(Integer, primary_key=True)
    name = Column(String)
    timestamp = Column(DateTime, default=datetime.datetime.utcnow)
    product_name = Column(String)
    serial_number = Column(String)
    total_tests = Column(Integer)
    completed_tests = Column(Integer)
    console = Column(Text)
    report_id = Column(Integer)
    testcases = relationship('Testcase', backref='testsuite')
    result = Column(String)

    def __init__(self, testsuite_name, product_name, serial_number, total_tests=0):
        self.name = testsuite_name
        self.product_name = product_name
        self.serial_number = serial_number
        self.total_tests = total_tests
        self.completed_tests = 0
        self.result = 'pending'

我读过我修改对象的方式可能会导致竞争状况，尽管我不确定是否合适。谁能指出我在做什么以及为什么messages不添加我的字符串的问题？

谢谢：）

迈克·怀尔德

因此，经过一番试验后，似乎代码失败了，因为它Testsuite.console没有初始值。

现在，代码可以对模式进行以下更改：

class Testsuite(Base):
    """Testsuite model to map testsuite in progress to SQL DB."""

    __tablename__ = 'testsuites'

    id = Column(Integer, primary_key=True)
    name = Column(String)
    timestamp = Column(DateTime, default=datetime.datetime.utcnow)
    product_name = Column(String)
    serial_number = Column(String)
    total_tests = Column(Integer)
    completed_tests = Column(Integer, default=0)
    console = Column(String, default="Waiting for incoming log data...\n")
    report_id = Column(Integer)
    testcases = relationship('Testcase', backref='testsuite')
    result = Column(String, default='pending')

    def __init__(self, testsuite_name, product_name, serial_number, total_tests=0):
        self.name = testsuite_name
        self.product_name = product_name
        self.serial_number = serial_number
        self.total_tests = total_tests