我试图用flask-restful制作rest api,我使用flask-sqlalchemy作为ORM。这是我的模型类。
class Post(db.Model):
__tablename__ = 'post'
postid = db.Column(db.Integer,primary_key=True)
post = db.Column(db.String(64))
userid = db.Column(db.Integer,db.ForeignKey('user.userid'))
#serialize property used for serializing this class to JSON
@property
def serialize(self):
return {
'postid': self.postid,
'post': self.post,
'author':self.author
}
和
class User(db.Model):
userid = db.Column(db.Integer,primary_key=True)
username = db.Column(db.String(30))
email = db.Column(db.String(20))
posts = db.relationship('Post',backref="author",lazy='dynamic')
#serialize property used for serializing this class to JSON
@property
def serialize(self):
return {
'username': self.username,
'email': self.email
}
并且数据库已填充。现在我正在尝试从中制作 json
class PostList(Resource):
def get(self):
posts = DL_models.Post.query.all()
posts = [post.serialize for post in posts]
return { 'posts': posts }
api.add_resource(PostList, '/twitter/api/v1.0/posts', endpoint = 'posts')
当我将 Post 中的序列化方法更改为
@property
def serialize(self):
return {
'postid': self.postid,
'post': self.post,
'author':self.postid
}
这会返回预期的 json 输出,但是当我更改'author':self.author
为时出现错误
TypeError: <app.DL_models.User object at 0x7f263f3adc10> is not JSON serializable
我知道我也必须对那些嵌套对象调用序列化,但我不知道该怎么做。
或者请分享您在 sqlalchemy 中编码关系的经验。