How to create a Model with a filed not int table.

[zhiguoxu]

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Example Code

from sqlmodel import SQLModel, Field, Session, create_engine

class User(SQLModel, table=True):
    id: int | None = Field(default=None, primary_key=True)
    username: str
    password: str
    # try to exclude token from table, but it would't work.
    token: str = Field(default=None, exclude=True)

# 创建数据库和表
engine = create_engine("sqlite:///demo.db")
SQLModel.metadata.create_all(engine)

user = User(username="admin", password="secret", token="abc123")

with Session(engine) as session:
    session.add(user)
    session.commit()

Description

How can I create a model with a filed not in table.
I have tried exclude=True, but it would't work.

Operating System

macOS

Operating System Details

No response

SQLModel Version

0.0.24

Python Version

3.10

Additional Context

No response

[monchin]

https://fastapi.tiangolo.com/tutorial/sql-databases/#create-multiple-models
Read from here carefully and this may help you

[janas-adam]

hi @zhiguoxu,

imo u lookin for pydantic PrivateAttr which is not released yet:

class SomeName(SQLModel, table=True):
    _field_name: str = PrivateAttr(default=None)  # not included in db

issues:

1. How to mark a model field as "non-persisted", i.e. to not be pushed to the DB? #147
2. Pydantic.PrivateAttr default and default_factory are ignored by SQLModel #149

pr (still in progress)

1. Adding _init_private_attributes to SQLModel __init__ function. #472

---

but, if u want to add this field at all cost u can use:

• double underscores

class SomeName(SQLModel, table=True):
    __field_name__: str

• or just inherit model with a new field

[YuriiMotov]

https://fastapi.tiangolo.com/tutorial/sql-databases/#create-multiple-models

Create one more model (use inheritance to reduce duplication):

class UserBase(SQLModel):
    id: int | None = Field(default=None, primary_key=True)
    username: str
    password: str

class User(UserBase, table=True):
    pass

class UserPublic(UserBase):
    token: Optional[str] = Field(default=None)

Then use UserPublic to validate and serialize data, and use User to store\query data:

from typing import Optional
from sqlmodel import SQLModel, Field, Session, create_engine


class UserBase(SQLModel):
    id: int | None = Field(default=None, primary_key=True)
    username: str
    password: str

class User(UserBase, table=True):
    pass


class UserPublic(UserBase):
    token: Optional[str] = Field(default=None)


engine = create_engine("sqlite:///demo.db")
SQLModel.metadata.create_all(engine)

user_public = UserPublic(username="admin", password="secret", token="abc123")
user = User.model_validate(user_public)

with Session(engine) as session:
    session.add(user)
    session.commit()