Set default schema to use for models/tables

[mfrey777]

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Example Code

from typing import AsyncGenerator

from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine
from sqlalchemy.orm import sessionmaker

from app.core import settings

log = logging.getLogger(__name__)

engine_async = create_async_engine(
    settings.DATABASE_URL_ASYNC, echo=False, future=True, query_cache_size=100
)

session_factory = sessionmaker(
    bind=engine_async, class_=AsyncSession, autoflush=False, expire_on_commit=False
)

async def get_session() -> AsyncGenerator[AsyncSession, None]:
    try:
        db: AsyncSession = session_factory()
        yield db
    finally:
        await db.close()

Description

Hello,

I am developing a multi-tenant system where each tenant will have it's own schema

I have a "shared" schema for couple of central tables and then one schema per tenant.

In SQLModel, I have set the "shared" schema for my central tables
table_args = {"schema": "shared"}

but would like to avoid adding:
table_args = {"schema": "tenant"}

to all my tables, because I would then also have to add the schema to all my foreign keys
status_id: int = Field(foreign_key="status.id")

I do not let SQLModel create the tables but use alembic for that : I will have to replace the dummy "tenant" will a real tenant name (and generate the tables for each new tenant), but it would like to avoid also having to update all the foreign keys

I found the following command to set the default schema in SQL Alchemy, but I am not sure where (and if) and I can use that with SQLModel and if it would actually works as expected (so that my foreign keys will also use the default schema if not explicetly specified)

metadata = sa.MetaData(schema="tenant")
Base = declarative_base(metadata=metadata)

I have put in the example code above the code I am using to setup the async engine / session.

Can this be achieved ?

Operating System

Windows

Operating System Details

Ubuntu 20.04 (WSL2)

SQLModel Version

0.0.8

Python Version

3.10.2

Additional Context

No response