无法通过Flask SQLAlchemy插入新记录

Question

当我尝试通过flask sqlalchemy向表中插入一个新行时，我收到以下错误。我只在尝试插入新行时看到此错误。我可以毫无问题地查询现有行。

ProgrammingError: (psycopg2.ProgrammingError) can't adapt type 'builtin_function_or_method' [SQL: 'INSERT INTO beaches (id, beach_name, lat, long, beach_description) VALUES (%(id)s, %(beach_name)s, %(lat)s, %(long)s, %(beach_description)s)'] [parameters: {'lat': 45.01, 'beach_description': 'some stuff here', 'id': <built-in function id>, 'long': 45.01, 'beach_name': 'test'}] (Background on this error at: http://sqlalche.me/e/f405)

这是我在模型文件中定义“beach”类的代码。

class Beach(db.Model):

    __tablename__ = 'beaches'

    id = db.Column(db.Integer, primary_key=True)
    beach_name = db.Column(db.String(256))
    lat = db.Column(db.Numeric)
    long = db.Column(db.Numeric)
    beach_description = db.Column(db.String(256))

    def __init__(self, id, beach_name, lat, long, beach_description):
        self.id = id
        self.beach_name = beach_name
        self.lat = lat
        self.long = long
        self.beach_description = beach_description

这是我创建类的实例并尝试插入db的代码。

beach_name = "test"
lat = 45.01
long = 45.01
beach_description = "some stuff here"

new_beach = Beach(id, beach_name, lat, long, beach_description)

db.session.add(new_beach)
db.session.commit()

这是我要插入的表的架构。我正在使用Postgres。

CREATE TABLE beaches (
    id SERIAL PRIMARY KEY,
    beach_name text,
    lat double precision,
    long double precision,
    beach_description text
);

有一个similar-looking post，评论者建议在创建类的实例时删除“id”。对我来说，看起来像下面的代码。我尝试过这种变化，但我得到了同样的错误。

beach_name = "test"
lat = 45.01
long = 45.01
beach_description = "some stuff here"

new_beach = Beach(beach_name, lat, long, beach_description)

db.session.add(new_beach)
db.session.commit()

即使上面的建议不起作用，我建议问题是在我的表中使用自动递增id列的某个地方。谢谢你的建议！

Answer 1

如果有人遇到类似的问题......

解决方案是从参数列表中删除'id'，从Beach类中删除self.id = id位，并在创建Beach类的新实例时删除'id'。

我想由于海滩表配置为在添加新记录时自动增加id（通过串行数据类型），因此在创建类的新实例时不必提供id。

该类的修订代码如下所示。

class Beach(db.Model):

    __tablename__ = 'beaches'

    id = db.Column(db.Integer, primary_key=True)
    beach_name = db.Column(db.String(256))
    lat = db.Column(db.Numeric)
    long = db.Column(db.Numeric)
    beach_description = db.Column(db.String(256))

    def __init__(self, beach_name, lat, long, beach_description):
        self.beach_name = beach_name
        self.lat = lat
        self.long = long
        self.beach_description = beach_description

在创建新实例并将其添加到db时，它应该看起来像这样......

beach_name = "test"
lat = 45.01
long = 45.01
beach_description = "some stuff here"

new_beach = Beach(beach_name, lat, long, beach_description)

db.session.add(new_beach)
db.session.commit()