Python-sqlalchemy.exc.ArgumentError:无法为映射表组装任何主键列

我正在使用Flask+Alembic+Sqlalchemy。我想创建两个表并使用它。首先，我运行alembic脚本：

"""add table insurace_bands and insurace_discounts

Revision ID: 39ba7ec3428
Revises: 18468fbedbac
Create Date: 2015-05-12 09:10:05.175513

"""

# revision identifiers, used by Alembic.
revision = '39ba7ec3428'
down_revision = '18468fbedbac'

from alembic import op
import sqlalchemy as sa

def upgrade():

        op.create_table('insurance_bands',

                sa.Column('id', sa.Integer(), nullable=False),

                sa.Column('name', sa.String(length=1024), nullable=False),

                sa.Column('product_price', sa.Numeric(precision=6, scale=2)),

                sa.Column('monthly_price', sa.Numeric(precision=6, scale=2)),

                sa.Column('active', sa.Boolean(), nullable=False, server_default='1'),

                sa.PrimaryKeyConstraint('id')
                )

    op.create_table('insurance_discounts',

                sa.Column('id', sa.Integer(), nullable=False),

                sa.Column('name', sa.String(length=1024), nullable=False),

                sa.Column('min_products', sa.Integer()),

                sa.Column('max_products', sa.Integer()),

                sa.Column('discount', sa.Numeric(precision=6, scale=2)),

                sa.Column('active', sa.Boolean(), nullable=False, server_default='1'),

                sa.PrimaryKeyConstraint('id')
                )

def downgrade():

    op.drop_table(
    'insurance_bands'
    )


    op.drop_table(
    'insurance_discounts'
    )

此脚本运行正常。然后，我创建了如下两个模型：

# -*- coding: utf-8 -*-
"""
    admin.insurance_brands.models
    ~~~~~~~~~~~~~~~~~~~~~

    insurance brand models
"""

from ..core import db
from ..helpers import JsonSerializer


class InsuranceBandJsonSerializer(JsonSerializer):
    __json_public__ = ['id', 'name', 'product_price', 'monthly_price', 'active']


class InsuranceBand(InsuranceBandJsonSerializer, db.Model):

    __tablename__ = 'insurance_bands'

    id = db.Column(db.Integer(), primary_key=True),
    name = db.Column(db.Unicode(1024)),
    product_price = db.Column(db.Numeric(precision=6, scale=2)),
    monthly_price = db.Column(db.Numeric(precision=6, scale=2)),
    active = db.Column(db.Boolean, default=True)


class InsuranceDiscountJsonSerializer(JsonSerializer):
    __json_public__ = ['id', 'name', 'min_products', 'max_products', 'active']


class InsuranceDiscount(InsuranceDiscountJsonSerializer, db.Model):

    __tablename__ = 'insurance_discounts'

    id = db.Column(db.Integer(), primary_key=True),
    name = db.Column(db.Unicode(1024)),
    min_products = db.Column(db.Integer()),
    max_products = db.Column(db.Integer()),
    active = db.Column(db.Boolean, default=True)

但当我运行server:python wsgi.py时，它抛出错误：

sqlalchemy.exc.ArgumentError:映射器映射器|保险带|保险带无法为映射表“保险带”组合任何主键列

这个模型似乎没有主键，但我定义了它

---

有人能帮我吗。提前感谢。

在您的课程中，您必须删除

，

之后的

）

---

你能试着去掉字段声明末尾的逗号并试试吗？@JRajan，啊，你说得对，我的错。非常感谢：D。

class InsuranceBand(InsuranceBandJsonSerializer, db.Model):

    __tablename__ = 'insurance_bands'

    id = db.Column(db.Integer(), primary_key=True)
    name = db.Column(db.Unicode(1024))
    product_price = db.Column(db.Numeric(precision=6, scale=2))
    monthly_price = db.Column(db.Numeric(precision=6, scale=2))
    active = db.Column(db.Boolean, default=True)