Is dynamic schema supported like in SQLAlchemy? #50

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1. aghanti7

   added

   questionFurther information is requestedFurther information is requested

   on Aug 28, 2021
2. RobertRosca commented on Nov 18, 2021

   

   RobertRosca

   on Nov 18, 2021

   Contributor

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   Would PR #43 solve this when merged?
3. aghanti7 commented on Nov 19, 2021

   

   aghanti7

   on Nov 19, 2021

   Author

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   I was able to achieve this with the below workaround.

   class UserActivityBase(SQLModel):
       # One table per user
       # Created first time when a user logs in perhaps
       created_ts: datetime.datetime = Field(primary_key=True)
       activity_type: str
       activity_value: float
   
   
   async def create_user_activity_model(uuid: str, engine: AsyncEngine):
       class UserActivity(UserActivityBase, table=True):
           __tablename__ = 'user_activity_' + uuid
           __table_args__ = {'schema': 'user_schema',
                                          'keep_existing': True}
   
       # Create the table if needed
       async with engine.begin() as conn:
           await conn.run_sync(SQLModel.metadata.create_all)
       return UserActivity
   
   
   class UserActivityCrud(UserActivityBase):
       pass
   
   
   async def get_user_activity_model(uuid: str):
       class UserActivityCrud(UserActivityBase, table=True):
           __tablename__ = 'user_activity_' + uuid
           __table_args__ = {'schema': 'user_schema',
                                          'keep_existing': True}
   
       return UserActivityCrud
   

   UserActivityBase is the base SQLModel. When you want to create the table for a new user, you can call create_user_activity_model() with the user's uuid and the engine instance. Later, when you need to get the model for a particular user, just call get_user_activity_model(uuid=<uuid>).

   The only thing I am facing is a warning. When you call get_user_activity_model more than once, the below warning is thrown.

   /Users/ghanti/code/proj/venv/lib/python3.9/site-packages/sqlmodel/main.py:367: SAWarning: This declarative base already contains a class with the same class name and module name as app.models.UserActivityCrud, and will be replaced in the string-lookup table.
   

   I feel this can be ignored. @tiangolo can you please confirm?
4. fastapi

   locked and limited conversation to collaborators on May 18, 2026
5. tiangolo

   converted this issue into a discussion #1920 on May 18, 2026