✨ Add source examples for docs

docs_src/tutorial/relationship_attributes/define_relationship_attributes/tutorial001.py

@@ -0,0 +1,70 @@
+from typing import List, Optional
+
+from sqlmodel import Field, Relationship, Session, SQLModel, create_engine
+
+
+class Team(SQLModel, table=True):
+    id: Optional[int] = Field(default=None, primary_key=True)
+    name: str
+    headquarters: str
+
+    heroes: List["Hero"] = Relationship(back_populates="team")
+
+
+class Hero(SQLModel, table=True):
+    id: Optional[int] = Field(default=None, primary_key=True)
+    name: str
+    secret_name: str
+    age: Optional[int] = None
+
+    team_id: Optional[int] = Field(default=None, foreign_key="team.id")
+    team: Optional[Team] = Relationship(back_populates="heroes")
+
+
+sqlite_file_name = "database.db"
+sqlite_url = f"sqlite:///{sqlite_file_name}"
+
+engine = create_engine(sqlite_url, echo=True)
+
+
+def create_db_and_tables():
+    SQLModel.metadata.create_all(engine)
+
+
+def create_heroes():
+    with Session(engine) as session:
+        team_preventers = Team(name="Preventers", headquarters="Sharp Tower")
+        team_z_force = Team(name="Z-Force", headquarters="Sister Margaret’s Bar")
+
+        hero_deadpond = Hero(
+            name="Deadpond", secret_name="Dive Wilson", team=team_z_force
+        )
+        hero_rusty_man = Hero(
+            name="Rusty-Man", secret_name="Tommy Sharp", age=48, team=team_preventers
+        )
+        hero_spider_boy = Hero(name="Spider-Boy", secret_name="Pedro Parqueador")
+        session.add(hero_deadpond)
+        session.add(hero_rusty_man)
+        session.add(hero_spider_boy)
+        session.commit()
+
+        session.refresh(hero_deadpond)
+        session.refresh(hero_rusty_man)
+        session.refresh(hero_spider_boy)
+
+        print("Created hero:", hero_deadpond)
+        print("Created hero:", hero_rusty_man)
+        print("Created hero:", hero_spider_boy)
+
+        hero_spider_boy.team = team_preventers
+        session.add(hero_spider_boy)
+        session.commit()
+
+
+def main():
+    create_db_and_tables()
+    create_heroes()
+
+
+if __name__ == "__main__":
+    main()