Python 烧瓶炼金术多对多插入
我尝试了上面的建议,但在插入带有标记的新帖子时,在附加多对多属性时继续收到以下错误 任何方向都将不胜感激 1: 下午6:22:22 web.1 |post.tags.append(post\u标记) 11:06:22 PM web.1 |文件“/home/trevor/Projects/trevorbog/venv/local/lib/python2.7/site packages/sqlalchemy/orm/collections.py”,第1072行,在附录中 晚上11:06:22 web.1 |项目=u集(自我、项目、发起人) 11:06:22 PM web.1 |文件“/home/trevor/Projects/trevorbog/venv/local/lib/python2.7/site packages/sqlalchemy/orm/collections.py”,第1044行,在| u集 晚上11:06:22 web.1 |项目=执行者。火灾附加事件(项目,发起人) 11:06:22 PM web.1 |文件“/home/trevor/Projects/trevorbog/venv/local/lib/python2.7/site packages/sqlalchemy/orm/collections.py”,第716行,火灾事件 晚上11:06:22 web.1 |项目,发起人) 11:06:22 PM web.1 |文件“/home/trevor/Projects/trevorbog/venv/local/lib/python2.7/site packages/sqlalchemy/orm/attributes.py”,第936行,在fire|append|事件中 11:06:22 PM web.1 |发起人或自身。_append_token或self。_init_append_token() 11:06:22 PM web.1 |文件“/home/trevor/Projects/trevorbog/venv/local/lib/python2.7/site packages/sqlalchemy/orm/attributes.py”,第1171行,在emit_backref_from_collection_append_事件中 晚上11:06:22 web.1 | child_state,child_dict=实例_state(child)\ 11:06:22 PM web.1 | AttributeError:'BaseQuery'对象没有属性'_sa_instance_state' Model.pyPython 烧瓶炼金术多对多插入,python,sqlalchemy,flask-sqlalchemy,Python,Sqlalchemy,Flask Sqlalchemy,我尝试了上面的建议,但在插入带有标记的新帖子时,在附加多对多属性时继续收到以下错误 任何方向都将不胜感激 1: 下午6:22:22 web.1 |post.tags.append(post\u标记) 11:06:22 PM web.1 |文件“/home/trevor/Projects/trevorbog/venv/local/lib/python2.7/site packages/sqlalchemy/orm/collections.py”,第1072行,在附录中 晚上11:06:22 web
blog_tag = db.Table('post_tag',
db.Column('post_id', db.Integer, db.ForeignKey('post.id')),
db.Column('tag_id', db.Integer, db.ForeignKey('tag.id'))
)
class Post(db.Model):
"""SQLAlchemy Post object class"""
id = db.Column(db.Integer, primary_key=True)
body = db.Column(db.Text)
timestamp = db.Column(db.DateTime)
title = db.Column(db.String(50))
author = db.Column(db.Integer, db.ForeignKey('user.id'))
uuid = db.Column(db.String(255))
tags = db.relationship('Tag',secondary=blog_tag,
back_populates="posts")
class Tag(db.Model):
"""SQLAlchemy Tag object class"""
id=db.Column(db.Integer, primary_key=True)
name=db.Column(db.String, unique=True, nullable=False)
posts = db.relationship('Post', secondary = blog_tag,
back_populates = "tags")
Views.py
@console.route('/new_post', methods=['GET', 'POST'])
@login_required
def new_post():
post_form = PostForm()
if post_form.validate_on_submit():
"""Take the list of tags and turn them into an array"""
uid = uuid.uuid4()
post = Post()
post.title = post_form.title.data
post.body = post_form.body.data
post.timestamp = datetime.utcnow()
post.author = current_user.id
post.uuid = uid.hex
tag_string = post_form.tags.data
tags = tag_string.split(",")
for tag in tags:
post_tag = add_tags(tag)
print post_tag
post.tags.append(post_tag)
db.session.add(post)
db.session.commit()
flash (u'New Post Created!', 'alert-info')
return render_template('new_post.html',
title='Admin-New Post',
form=post_form)
def add_tags(tag):
existing_tag = Tag.query.filter(Tag.name == tag.lower())
"""if it does return existing tag objec to list"""
if existing_tag is not None:
return existing_tag
else:
new_tag = Tag()
new_tag.name = tag.lower()
return new_tag
这:
不返回
标记
,而是返回查询
。您需要Tag.query.filter(…).one\u或\u none()
来获取标记本身。谢谢!明白了,回到文档,我去弄清楚查询是如何工作的。
existing_tag = Tag.query.filter(Tag.name == tag.lower())
"""if it does return existing tag objec to list"""
if existing_tag is not None:
return existing_tag