SqlAlchemy, how to make automatic join
I got 3 tables
class Article_Comment(Base):
__tablename__ = 'article_comment'
article_id = Column(Integer, ForeignKey('article.id'), primary_key=True)
comment_id = Column(Integer, ForeignKey('comment.id'), primary_key=True)
child = relationship("Comment", lazy="joined", innerjoin=True)
class Article(Base):
__tablename__ = 'article'
id = Column(Integer, primary_key=True)
title = Column(String)
children = relationship("Article_Comment", lazy="joined", innerjoin=True)
class Comment(Base):
__tablename__ = 'comment'
id = Column(Integer, primary_key=True)
text = Column(String)
I need to get specific Article with Comments. I do this like this:
Session = sessionmaker(bind=engine)
session = Session()
result = session.query(Article, Comment).join(Article_Comment).join(Comment).filter(Article_Comment.article_id == Article.id).filter(Article_Comment.comment_id == Comment.id).filter(Article.title=='music').all()
for i, j in result:
print i.title, j.text
But I want to make this query without using .join.
Can someone help me?
May be, I need to remake relationships?
Asked by: Emma275 | Posted: 06-12-2021
Answer 1
My thx to univerio
Here is the full answer
set up a relationship on Article, comments = relationship(Comment, secondary=Article_Comment.__table__, lazy="joined")
session.query(Article).filter(Article.title=='music').one().comments
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