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Issue using from_orm stripping Relationship data from models #224
Description
First Check
- I added a very descriptive title to this issue.
- I used the GitHub search to find a similar issue and didn't find it.
- I searched the SQLModel documentation, with the integrated search.
- I already searched in Google "How to X in SQLModel" and didn't find any information.
- I already read and followed all the tutorial in the docs and didn't find an answer.
- I already checked if it is not related to SQLModel but to Pydantic.
- I already checked if it is not related to SQLModel but to SQLAlchemy.
Commit to Help
- I commit to help with one of those options 👆
Example Code
from sqlmodel import SQLModel, Relationship, Field, create_engine, Session
from typing import List, Optional, Literal
engine = create_engine("sqlite://", connect_args={"check_same_thread": False})
def create_db_and_tables():
SQLModel.metadata.create_all(engine)
class LocationBase(SQLModel):
street: str
city: str
country: str
class Location(SQLModel, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
employee_id: Optional[int] = Field(default=None, foreign_key="employee.id")
employee: "Employee" = Relationship(back_populates='locations')
class EmployeeBase(SQLModel):
name: str
job: str
class Employee(EmployeeBase, table=True):
id: Optional[int] = Field(default=None, primary_key=True)
locations: List[Location] = Relationship(back_populates="employee")
class EmployeeCreate(EmployeeBase):
locations: List[Location]
def create_employees():
locations = [Location(street='State St.', city='New York', country='USA')]
e = EmployeeCreate(name='Test Employee', job='Test Job', locations=locations)
employee = Employee.from_orm(e) # this strips the locations list from the Employee object
print(employee)
# You have to manually readd the locations before sending data to the DB.
# If you skip this line then no location data will be added to the DB.
e.locations = locations
# Now you can commit.
def main():
create_db_and_tables()
create_employees()
if __name__ == "__main__":
main()Description
Apologies if this seems trivial! When using SQLModel's from_orm method the relationship data is stripped from the outputted model. I think that there may be an issue with how the from_orm method works in SQLModel but I can't diagnose where the data is actually stripped.
I found a similar issue here: pydantic/pydantic#1334. The difference is that typically (before SQLModel) most models refer to other Pydantic models instead of other relationships. This could be an example of a typical model relationship in Pydantic:
from pydantic import BaseModel
class Employee(BaseModel):
id: int
name: str
type: str
class Address(BaseModel):
id: int
city: str
employee: Employee
class Config:
orm_mode = True
e = Employee(id=1, name='Test', type='pydantic')
a= Address(id=1, city='New York', employee=e)
print(a.from_orm(a))
(This correctly outputs id=1 city='New York' employee=Employee(id=1, name='Test', type='pydantic'))
It's not a big deal to readd the models but it becomes tedious if you have many models to manage. I was wondering if anyone else had this issue and I couldn't find it referenced anywhere else. Thank you so much!
Operating System
macOS
Operating System Details
No response
SQLModel Version
0.0.6
Python Version
3.8.1
Additional Context
No response
Activity
mafetoro92 commented on Jan 17, 2022
I am having the same issue too
Butch78 commented on Feb 5, 2022
I was having the same issue, I'm confused why you are able to add Objects with children here in the Docs:
But in the Fastapi + SQLmodel example there is no example of how to solve this solution only if you want to read from the Database:
I'm assuming the Advanced guide might have a solution for how you create models with children. Unless I'm misunderstanding how you should create objects? but I assume you would want an endpoint to behave like @res234's create employee function:
E.g:
res234 commented on Feb 5, 2022
@Butch78 I think we are having different issues.
In your first code example, you can add objects with children because you are creating the Team object directly. My example is a little different because I am creating an EmployeeCreate object and then using the from_orm method in Pydantic. The from_orm method strips out the child data when making the Employee SQLModel object. So I can use from_orm to serialize part of the Employee object but I have to add the locations of the employee manually using employee.locations and then commit.
The docs do give an example of how to read from the database with children: https://sqlmodel.tiangolo.com/tutorial/fastapi/relationships/#models-with-relationships
My issues is strictly with the from_orm method only. Apologies if I'm misunderstanding your questions.
Butch78 commented on Feb 5, 2022
Sorry my answer wasn't very clear @res234, I would like to do the same as you and I agree the 'from_orm' Doesn't quite work right. I would like to Convert Json or TeamCreate objects into a SQLModel using 'from_orm' that can then be added to the database instead of having to manually add it.
res234 commented on Feb 5, 2022
@Butch78 No problem!
dansmachina commented on Feb 21, 2022
Facing the same challenge here... :-)
Phifo commented on Nov 16, 2022
same issue here 😢
ckudera commented on Jun 14, 2023
I'm facing the same issue. Any updates?
JeffTax commented on Aug 8, 2023
I'm here for the same reason, was debugging and found out nested objects were being stripped. This is not intuitive at all, and I came across https://github.com/Wouterkoorn/sqlalchemy-pydantic-orm, but this should be a core feature of SQLModel IMO.
whugarra commented on Jul 15, 2024
same issue here 😢
prurph commented on Jul 20, 2024
Yeah this bit me as well.
YuriiMotov commented on Aug 27, 2025
This is basically a duplicate of #6.
Lets's track this issue there