📝 Add source examples for Python 3.9 and 3.10 (#715)

* 📝 Add source examples for Python 3.9 and 3.10

* ✅ Add tests for new source examples for Python 3.9 and 3.10, still needs pytest markers

* ✅ Add tests for fastapi examples

* ✅ Update tests for FastAPI app testing, for Python 3.9 and 3.10, fixing multi-app testing conflicts

* ✅ Require Python 3.9 and 3.10 for tests

* ✅ Update tests with missing markers

docs_src/tutorial/code_structure/tutorial002_py310/app.py

@@ -0,0 +1,30 @@
+from sqlmodel import Session
+
+from .database import create_db_and_tables, engine
+from .hero_model import Hero
+from .team_model import Team
+
+
+def create_heroes():
+    with Session(engine) as session:
+        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
+        )
+        session.add(hero_deadpond)
+        session.commit()
+
+        session.refresh(hero_deadpond)
+
+        print("Created hero:", hero_deadpond)
+        print("Hero's team:", hero_deadpond.team)
+
+
+def main():
+    create_db_and_tables()
+    create_heroes()
+
+
+if __name__ == "__main__":
+    main()

docs_src/tutorial/code_structure/tutorial002_py310/database.py

@@ -0,0 +1,10 @@
+from sqlmodel import SQLModel, create_engine
+
+sqlite_file_name = "database.db"
+sqlite_url = f"sqlite:///{sqlite_file_name}"
+
+engine = create_engine(sqlite_url)
+
+
+def create_db_and_tables():
+    SQLModel.metadata.create_all(engine)

docs_src/tutorial/code_structure/tutorial002_py310/hero_model.py

@@ -0,0 +1,16 @@
+from typing import TYPE_CHECKING, Optional
+
+from sqlmodel import Field, Relationship, SQLModel
+
+if TYPE_CHECKING:
+    from .team_model import Team
+
+
+class Hero(SQLModel, table=True):
+    id: int | None = Field(default=None, primary_key=True)
+    name: str = Field(index=True)
+    secret_name: str
+    age: int | None = Field(default=None, index=True)
+
+    team_id: int | None = Field(default=None, foreign_key="team.id")
+    team: Optional["Team"] = Relationship(back_populates="heroes")

docs_src/tutorial/code_structure/tutorial002_py310/team_model.py

@@ -0,0 +1,14 @@
+from typing import TYPE_CHECKING
+
+from sqlmodel import Field, Relationship, SQLModel
+
+if TYPE_CHECKING:
+    from .hero_model import Hero
+
+
+class Team(SQLModel, table=True):
+    id: int | None = Field(default=None, primary_key=True)
+    name: str = Field(index=True)
+    headquarters: str
+
+    heroes: list["Hero"] = Relationship(back_populates="team")