<p>不能将对象本身存储在数据库中。您要做的是存储对象中的数据并在以后重新构建它。</p>
<p>一个好的方法是使用优秀的<a href="http://www.sqlalchemy.org" rel="noreferrer">SQLAlchemy</a>库。它允许您将定义的类映射到数据库中的表。每个映射的属性都将被存储,并可用于重建对象。查询数据库将返回类的实例。</p>
<p>有了它,您不仅可以使用sqlite,还可以使用大多数数据库——它目前还支持Postgres、MySQL、Oracle、MS-SQL、Firebird、MaxDB、MS-Access、Sybase、Informix和IBM DB2。你可以让你的用户选择她想使用哪一个,因为你基本上可以在这些数据库之间切换,而不需要改变代码。</p>
<p>还有很多很酷的特性,比如自动<code>JOIN</code>,多态性。。。</p>
<p>一个简单快速的示例,您可以运行:</p>
<pre><code>from sqlalchemy import Column, Integer, Unicode, UnicodeText, String
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
from random import choice
from string import letters
engine = create_engine('sqlite:////tmp/teste.db', echo=True)
Base = declarative_base(bind=engine)
class User(Base):
__tablename__ = 'users'
id = Column(Integer, primary_key=True)
name = Column(Unicode(40))
address = Column(UnicodeText, nullable=True)
password = Column(String(20))
def __init__(self, name, address=None, password=None):
self.name = name
self.address = address
if password is None:
password = ''.join(choice(letters) for n in xrange(10))
self.password = password
Base.metadata.create_all()
Session = sessionmaker(bind=engine)
s = Session()
</code></pre>
<p>然后我可以这样使用它:</p>
<pre><code># create instances of my user object
u = User('nosklo')
u.address = '66 Some Street #500'
u2 = User('lakshmipathi')
u2.password = 'ihtapimhskal'
# testing
s.add_all([u, u2])
s.commit()
</code></pre>
<p>这将对数据库运行<code>INSERT</code>语句。</p>
<pre><code># When you query the data back it returns instances of your class:
for user in s.query(User):
print type(user), user.name, user.password
</code></pre>
<p>该查询将运行<code>SELECT users.id AS users_id, users.name AS users_name, users.address AS users_address, users.password AS users_password</code>。</p>
<p>打印结果如下:</p>
<pre><code><class '__main__.User'> nosklo aBPDXlTPJs
<class '__main__.User'> lakshmipathi ihtapimhskal
</code></pre>
<p>因此,您可以有效地将对象存储到数据库中,这是最好的方法。</p>