知识资产管理系统

<pre><code>

# 导入必要的库

from sqlalchemy import create_engine, Column, Integer, String, ForeignKey

from sqlalchemy.ext.declarative import declarative_base

from sqlalchemy.orm import sessionmaker, relationship

# 创建基础类

Base = declarative_base()

# 定义用户表

class User(Base):

__tablename__ = 'users'

id = Column(Integer, primary_key=True)

username = Column(String(50), unique=True)

# 定义文档表

class Document(Base):

__tablename__ = 'documents'

id = Column(Integer, primary_key=True)

title = Column(String(100))

user_id = Column(Integer, ForeignKey('users.id'))

user = relationship("User", back_populates="documents")

# 用户与文档建立关系

User.documents = relationship("Document", order_by=Document.id, back_populates="user")

# 初始化数据库引擎

engine = create_engine('sqlite:///document_management.db')

Base.metadata.create_all(engine)

# 创建会话

Session = sessionmaker(bind=engine)

session = Session()

# 添加新用户

new_user = User(username='admin')

session.add(new_user)

session.commit()

# 添加新文档

new_doc = Document(title='项目计划', user_id=new_user.id)

session.add(new_doc)

session.commit()

# 查询所有文档

for doc in session.query(Document).all():

print(doc.title)

# 版本控制示例

class DocumentVersion(Base):

__tablename__ = 'document_versions'

id = Column(Integer, primary_key=True)

document_id = Column(Integer, ForeignKey('documents.id'))

content = Column(String(500))

document = relationship("Document", back_populates="versions")

Document.versions = relationship("DocumentVersion", order_by=DocumentVersion.id, back_populates="document")

# 云存储示例

import boto3

s3 = boto3.resource('s3')

s3.Bucket('your-bucket-name').put_object(Key='test.txt', Body=b'This is a test file.')

</code></pre>