modify structure

server/src/app/models/question.py

@@ -0,0 +1,12 @@
+from sqlmodel import Field, SQLModel, Relationship
+from src.app.models.knowledge import Knowledge
+#TODO : add pydantic validation
+
+class Question(SQLModel, table=True):
+    id: int | None = Field(default=None, primary_key=True)
+    question:str
+
+    knowledge_id: int | None = Field(default=None, foreign_key="knowledge.id", ondelete="CASCADE")
+    knowledge: Knowledge | None =  Relationship(back_populates="questions")
+
+    metrics: list["Metric"] = Relationship(back_populates="question", cascade_delete=True) # type: ignore