Test d'une association de 3 tables : pas abouti

relationship/association_object_ternary.py

+"""
+https://docs.sqlalchemy.org/en/14/orm/basic_relationships.html#association-object
+"""
+from datetime import datetime
+
+from sqlalchemy import create_engine
+from sqlalchemy import Column, ForeignKey, Integer, Text, DateTime
+from sqlalchemy.orm import declarative_base, relationship
+from sqlalchemy.orm.session import Session
+
+
+Base = declarative_base()
+
+
+class UserOrgRole(Base):
+    __tablename__ = "user_org_role"
+
+    user_id = Column(
+        ForeignKey("user.id", ondelete="CASCADE"), primary_key=True
+    )
+    org_id = Column(ForeignKey("org.id", ondelete="CASCADE"), primary_key=True)
+    # Does it make sense ?
+    role_id = Column(
+        ForeignKey("role.id", ondelete="CASCADE"), primary_key=True
+    )
+
+    # I do not know what the relationship could back populate, org or role ???
+    user = relationship("User")
+    org = relationship("Org")
+    role = relationship("Role")
+
+
+class User(Base):
+    __tablename__ = "user"
+
+    id = Column(Integer, primary_key=True)
+    username = Column(Text, index=True, nullable=False)
+    fullname = Column(Text, nullable=False)
+    account_type = Column(Text, nullable=False)
+
+    def __repr__(self):
+        return (
+            f"<User (username={self.username}, fullname={self.fullname}, "
+            f"account_type={self.account_type})>"
+        )
+
+
+class Org(Base):
+    __tablename__ = "org"
+
+    id = Column(Integer, primary_key=True)
+    name = Column(Text, index=True, nullable=False)
+    slug = Column(Text, index=True, nullable=False)
+    created_at = Column(DateTime)
+
+    def __repr__(self):
+        return (
+            f"<Org (name={self.name}, slug={self.slug}, "
+            f"created_at={self.created_at})>"
+        )
+
+
+class Role(Base):
+    __tablename__ = "role"
+
+    id = Column(Integer, primary_key=True)
+    name = Column(Text, index=True, nullable=False)
+
+    def __repr__(self):
+        return f"<Role (name={self.name})>"
+
+
+if __name__ == "__main__":
+    engine = create_engine(
+        "sqlite:///association_object_ternary.db", echo=False
+    )
+
+    Base.metadata.drop_all(engine)
+    Base.metadata.create_all(engine)
+
+    with Session(engine) as session:
+        # create parent, append a child via association
+        u1 = User(
+            username="jlondon",
+            fullname="Jack London",
+            account_type="member",
+        )
+        o1 = Org(name="o1", slug="o1", created_at=datetime.utcnow())
+        owner = Role(name="owner")
+
+        uor1 = UserOrgRole()
+        uor1.user = u1
+        uor1.org = o1
+        uor1.role = owner
+
+        with session.begin():
+            session.add(u1)
+            session.add(o1)
+            session.add(owner)
+
+            session.add(uor1)