Specify 'extend_existing=True' to redefine options and columns on an existing Table object.

[wanghaisheng]

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Example Code

from datetime import datetime
from typing import Optional, List

import sqlmodel
from fastapi_amis_admin.amis.components import InputRichText, InputImage, ColumnImage
from fastapi_amis_admin.models.enums import IntegerChoices
from fastapi_amis_admin.models.fields import Field
from fastapi_user_auth.auth.models import User
from sqlalchemy import Column, String


class VideoStatus(IntegerChoices):
    unpublished = 0, '未发布'
    published = 1, '已发布'
    inspection = 2, '审核中'
    disabled = 3, '已禁用'


# Create your models here.

class BaseSQLModel(sqlmodel.SQLModel):
    id: int = Field(default=None, primary_key=True, nullable=False)

    class Config:
        use_enum_values = True




class VideoPlatformLink(sqlmodel.SQLModel, table=True):
    __tablename__ = 'publish_video_platforms'
    platform_id: Optional[int] = Field(
        default=None, foreign_key="publish_platform.id", primary_key=True
    )
    video_id: Optional[int] = Field(
        default=None, foreign_key="publish_video.id", primary_key=True
    )

class VideoChannelLink(sqlmodel.SQLModel, table=True):
    __tablename__ = 'publish_video_channels'
    channel_id: Optional[int] = Field(
        default=None, foreign_key="publish_channel.id", primary_key=True
    )
    video_id: Optional[int] = Field(
        default=None, foreign_key="publish_video.id", primary_key=True
    )


class Platform(BaseSQLModel, table=True):
    __tablename__ = 'publish_platform'
    name: str = Field(..., title='PlatformName', sa_column=Column(String(255), unique=True, index=True, nullable=False))
    videos: List["Video"] = sqlmodel.Relationship(back_populates="platforms",link_model=VideoPlatformLink)
    channels: List["Channel"] = sqlmodel.Relationship(back_populates="platform")


class Channel(BaseSQLModel, table=True):
    __tablename__ = 'publish_channel'
    extend_existing=True
    name: str = Field(title='ChannelName', sa_column=Column(String(100), unique=True, index=True, nullable=False))
    description: str = Field(default='', title='Description', amis_form_item='textarea')
    status: bool = Field(None, title='status')
    videos: List["Video"] = sqlmodel.Relationship(back_populates="channels",link_model=VideoChannelLink)
    platform: Optional[Platform] = sqlmodel.Relationship(back_populates="channels")



class Video(BaseSQLModel, table=True):
    __tablename__ = 'publish_video'
    title: str = Field(title='VideoTitle', max_length=200)
    img: str = Field(None, title='VideoImage', max_length=300,
                     amis_form_item=InputImage(maxLength=1, maxSize=2 * 1024 * 1024,
                                               receiver='post:/admin/file/upload'),
                     amis_table_column=ColumnImage(width=100, height=60, enlargeAble=True))
    description: str = Field(default='', title='VideoDescription', amis_form_item='textarea')
    status: VideoStatus = Field(VideoStatus.unpublished, title='status')
    content: str = Field(..., title='VideoContent', amis_form_item=InputRichText())
    create_time: Optional[datetime] = Field(default_factory=datetime.utcnow, title='CreateTime')
    source: str = Field(default='', title='VideoSource', max_length=200)

    # channel_id: Optional[int] = Field(default=None, foreign_key="publish_channel.id", title='ChannelId')
    channels: List[Channel] = sqlmodel.Relationship(back_populates="videos",link_model=VideoChannelLink)

    platforms: List[Platform] = sqlmodel.Relationship(back_populates="videos", link_model=VideoPlatformLink)

    user_id: int = Field(default=None, foreign_key="auth_user.id", title='UserId')
    user: User = sqlmodel.Relationship()

Description

I want to achieve

1. one Platform has many videos ,one video has many platform
   so VideoPlatformLink to many-many link
2. one Platform has many channel,one channel has one platform
   so i use

    channels: List["Channel"] = sqlmodel.Relationship(back_populates="platform")

3.one channel has many videos, one video has many channels
so VideoChannelLink to many2many

it tell me

sqlalchemy.exc.InvalidRequestError: Table 'publish_channel' is already defined for this MetaData instance.  Specify 'extend_existing=True' to redefine options and columns on an existing Table object.

Operating System

Windows

Operating System Details

No response

SQLModel Version

0.0.6

Python Version

3.8.0

Additional Context

I have add ** extend_existing=True**
but it still tell me

sqlalchemy.exc.InvalidRequestError: Table 'publish_channel' is already defined for this MetaData instance.  Specify 'extend_existing=True' to redefine options and columns on an existing Table object.

[RobertRosca]

The example you gave has quite a lot of things going on, and a few external dependencies, so it's not too clear to me what the issue is.

Could you:

1. Post a minimum example that reproduces the issue - e.g. a script like those shown in the documentation which can be ran that generates the table and attempts to add some entries into it all in one go. Something that can just be executed with python3 ./issue.py makes it much easier to help out.
2. Post the output of python3 -m pip freeze - there have been some issues recently with newer versions of SQLAlchemy so this might be related. You can try pinning SQLAlchemy to a lower version (poetry install "sqlalchemy<=1.4.35") and see if that helps.

[lokeeshbharathi]

@wanghaisheng did you found solution for this issue and why it is occurring ?

[wanghaisheng]

@lokeeshbharathi never

[lokeeshbharathi]

@wanghaisheng It is occurring due to giving same __tablename__ = 'publish_channel in some other Class or Model.

[wanghaisheng]

@lokeeshbharathi I struggle a little time and give up . I will look my old code again to check that.thank you anyway

[wanghaisheng]

@lokeeshbharathi I struggle a little time and give up . I will look my old code again to check that.thank you anyway

[nilanjan-debnath]

You can't directly add extend_existing=True, just replace it with __table_args__ = {'extend_existing': True}
For connecting any existing table in the database you have to pass this argument to avoid this error.

class Channel(BaseSQLModel, table=True):
    __tablename__ = 'publish_channel'

    __table_args__ = {'extend_existing': True}   # add this as table arguments

    name: str = Field(title='ChannelName', sa_column=Column(String(100), unique=True, index=True, nullable=False))
    description: str = Field(default='', title='Description', amis_form_item='textarea')
    status: bool = Field(None, title='status')
    videos: List["Video"] = sqlmodel.Relationship(back_populates="channels",link_model=VideoChannelLink)
    platform: Optional[Platform] = sqlmodel.Relationship(back_populates="channels")