擅长:python、mysql、java
<p>要使用ORM,请创建一个会话
请参阅该文件</p>
<p><a href="https://docs.sqlalchemy.org/en/13/orm/tutorial.html" rel="nofollow noreferrer">https://docs.sqlalchemy.org/en/13/orm/tutorial.html</a></p>
<pre><code>from sqlalchemy import and_
q = session.query(Page, RolePage, Role) \
.outerjoin(RolePage, and_(RolePage.page_id == Page.page_id, Rolepage.role_id == 2)) \
.outerjoin(Role, Role.role_id == RolePage.role_id)
for _page, _role_page, _role in q:
print(_page, _role_page, _role)
</code></pre>