You have a Flask-SQLAlchemy relationship defined as lazy='joined', but your application still issues multiple queries when accessing related data. What is the most likely cause?
medium📝 Debug Q6 of 15
Flask - Performance Optimization
You have a Flask-SQLAlchemy relationship defined as lazy='joined', but your application still issues multiple queries when accessing related data. What is the most likely cause?
AThe relationship is not properly configured with back_populates.
BYou are accessing the related data before the parent query.
CThe query does not use <code>options(joinedload())</code> to enforce eager loading.
DYou forgot to import the related model.
Step-by-Step Solution
Solution:
Step 1: Understand eager loading enforcement
Even if lazy='joined' is set, the query must use options(joinedload()) to eagerly load related data.
Step 2: Identify cause of multiple queries
Without joinedload(), SQLAlchemy may still issue separate queries despite lazy='joined'.
Final Answer:
The query does not use options(joinedload()) to enforce eager loading. -> Option C
Quick Check:
Eager loading requires joinedload() in query [OK]
Quick Trick:Use options(joinedload()) to enforce eager loading [OK]
