💭 Create Models with a Many-to-Many Link - SQLModel
===================================================

!https://sqlmodel.tiangolo.com/tutorial/many-to-many/create-models-with-link/

Date: August 9, 2023

Create Models with a Many-to-Many Link - SQLModel
 SQLModel, SQL databases in Python, designed for simplicity, compatibility, and robustness.
 sqlmodel.tiangolo.com [1]

Creating many to many relationships with sqlmodel requires a LinkTable Model. The link model will keep track of the linked id's between each of the models.

``` python
from typing import List, Optional

from sqlmodel import Field, Relationship, Session, SQLModel, create_engine

class HeroTeamLink(SQLModel, table=True):
 team_id: Optional[int] = Field(
 default=None, foreign_key="team.id", primary_key=True
 )
 hero_id: Optional[int] = Field(
 default=None, foreign_key="hero.id", primary_key=True
 )

class Team(SQLModel, table=True):
 id: Optional[int] = Field(default=None, primary_key=True)
 name: str = Field(index=True)
 headquarters: str

 heroes: List["Hero"] = Relationship(back_populates="teams", link_model=HeroTeamLink)

class Hero(SQLModel, table=True):
 id: Optional[int] = Field(default=None, primary_key=True)
 name: str = Field(index=True)
 secret_name: str
 age: Optional[int] = Field(default=None, index=True)

 teams: List[Team] = Relationship(back_populates="heroes", link_model=HeroTeamLink)
```

!!! note

 This post is a thought [2]. It's a short note that I make
 about someone else's content online #thoughts [3]

References:
[1]: https://sqlmodel.tiangolo.com/tutorial/many-to-many/create-models-with-link/
[2]: /thoughts/
[3]: /tags/thoughts/