refactor: optimize functions queries

apps/api/src/services/courses/activities/activities.py

@@ -92,24 +92,21 @@ async def get_activity(
     current_user: PublicUser,
     db_session: Session,
 ):
-    statement = select(Activity).where(Activity.activity_uuid == activity_uuid)
+    # Optimize by joining Activity with Course in a single query
-    activity = db_session.exec(statement).first()
+    statement = (
+        select(Activity, Course)
+        .join(Course)
+        .where(Activity.activity_uuid == activity_uuid)
+    )
+    result = db_session.exec(statement).first()
 
-    if not activity:
+    if not result:
         raise HTTPException(
             status_code=404,
             detail="Activity not found",
         )
     
-    # Get course from that activity
+    activity, course = result
-    statement = select(Course).where(Course.id == activity.course_id)
-    course = db_session.exec(statement).first()
-
-    if not course:
-        raise HTTPException(
-            status_code=404,
-            detail="Course not found",
-        )
 
     # RBAC check
     await rbac_check(request, course.course_uuid, current_user, "read", db_session)
@@ -124,9 +121,8 @@ async def get_activity(
 
     activity_read = ActivityRead.model_validate(activity)
     activity_read.content = activity_read.content if has_paid_access else { "paid_access": False }
-    activity = activity_read
 
-    return activity
+    return activity_read
 
 async def get_activityby_id(
     request: Request,
@@ -134,31 +130,26 @@ async def get_activityby_id(
     current_user: PublicUser,
     db_session: Session,
 ):
-    statement = select(Activity).where(Activity.id == activity_id)
+    # Optimize by joining Activity with Course in a single query
-    activity = db_session.exec(statement).first()
+    statement = (
+        select(Activity, Course)
+        .join(Course)
+        .where(Activity.id == activity_id)
+    )
+    result = db_session.exec(statement).first()
 
-    if not activity:
+    if not result:
         raise HTTPException(
             status_code=404,
             detail="Activity not found",
         )
     
-    # Get course from that activity
+    activity, course = result
-    statement = select(Course).where(Course.id == activity.course_id)
-    course = db_session.exec(statement).first()
-
-    if not course:
-        raise HTTPException(
-            status_code=404,
-            detail="Course not found",
-        )
 
     # RBAC check
     await rbac_check(request, course.course_uuid, current_user, "read", db_session)
 
-    activity = ActivityRead.model_validate(activity)
+    return ActivityRead.model_validate(activity)
-
-    return activity
 
 
 async def update_activity(

apps/api/src/services/courses/courses.py

@@ -27,6 +27,7 @@ from src.security.rbac.rbac import (
 from src.services.courses.thumbnails import upload_thumbnail
 from fastapi import HTTPException, Request, UploadFile
 from datetime import datetime
+import asyncio
 
 
 async def get_course(
@@ -106,6 +107,7 @@ async def get_course_meta(
     # Avoid circular import
     from src.services.courses.chapters import get_course_chapters
 
+    # Get course with a single query
     course_statement = select(Course).where(Course.course_uuid == course_uuid)
     course = db_session.exec(course_statement).first()
 
@@ -118,36 +120,51 @@ async def get_course_meta(
     # RBAC check
     await rbac_check(request, course.course_uuid, current_user, "read", db_session)
 
-    # Get course authors
+    # Start async tasks concurrently
+    tasks = []
+    
+    # Task 1: Get course authors
+    async def get_authors():
         authors_statement = (
             select(User)
             .join(ResourceAuthor)
             .where(ResourceAuthor.resource_uuid == course.course_uuid)
         )
-    authors = db_session.exec(authors_statement).all()
+        return db_session.exec(authors_statement).all()
     
-    # convert from User to UserRead
+    # Task 2: Get course chapters
-    authors = [UserRead.model_validate(author) for author in authors]
+    async def get_chapters():
-
+        # Ensure course.id is not None
-    course = CourseRead(**course.model_dump(), authors=authors)
+        if course.id is None:
-
+            return []
-    # Get course chapters
+        return await get_course_chapters(request, course.id, db_session, current_user)
-    chapters = await get_course_chapters(request, course.id, db_session, current_user)
-
-    # Trail
-    trail = None
     
+    # Task 3: Get user trail (only for authenticated users)
+    async def get_trail():
         if isinstance(current_user, AnonymousUser):
-        trail = None
+            return None
-    else:
+        return await get_user_trail_with_orgid(
-        trail = await get_user_trail_with_orgid(
             request, current_user, course.org_id, db_session
         )
     
+    # Add tasks to the list
+    tasks.append(get_authors())
+    tasks.append(get_chapters())
+    tasks.append(get_trail())
+    
+    # Run all tasks concurrently
+    authors_raw, chapters, trail = await asyncio.gather(*tasks)
+    
+    # Convert authors from User to UserRead
+    authors = [UserRead.model_validate(author) for author in authors_raw]
+    
+    # Create course read model
+    course_read = CourseRead(**course.model_dump(), authors=authors)
+    
     return FullCourseReadWithTrail(
-        **course.model_dump(),
+        **course_read.model_dump(),
         chapters=chapters,
-        trail=trail if trail else None,
+        trail=trail,
     )
 
 async def get_courses_orgslug(
@@ -197,18 +214,33 @@ async def get_courses_orgslug(
 
     courses = db_session.exec(query).all()
     
-    # Fetch authors for each course
+    if not courses:
+        return []
+        
+    # Get all course UUIDs
+    course_uuids = [course.course_uuid for course in courses]
+    
+    # Fetch all authors for all courses in a single query
+    authors_query = (
+        select(ResourceAuthor, User)
+        .join(User, ResourceAuthor.user_id == User.id)  # type: ignore
+        .where(ResourceAuthor.resource_uuid.in_(course_uuids))  # type: ignore
+    )
+    
+    author_results = db_session.exec(authors_query).all()
+    
+    # Create a dictionary mapping course_uuid to list of authors
+    course_authors = {}
+    for resource_author, user in author_results:
+        if resource_author.resource_uuid not in course_authors:
+            course_authors[resource_author.resource_uuid] = []
+        course_authors[resource_author.resource_uuid].append(UserRead.model_validate(user))
+    
+    # Create CourseRead objects with authors
     course_reads = []
     for course in courses:
-        authors_query = (
-            select(User)
-            .join(ResourceAuthor, ResourceAuthor.user_id == User.id)  # type: ignore
-            .where(ResourceAuthor.resource_uuid == course.course_uuid)
-        )
-        authors = db_session.exec(authors_query).all()
-        
         course_read = CourseRead.model_validate(course)
-        course_read.authors = [UserRead.model_validate(author) for author in authors]
+        course_read.authors = course_authors.get(course.course_uuid, [])
         course_reads.append(course_read)
 
     return course_reads

apps/api/src/services/orgs/orgs.py

@@ -529,39 +529,31 @@ async def get_orgs_by_user_admin(
     page: int = 1,
     limit: int = 10,
 ) -> list[OrganizationRead]:
-
+    # Join Organization, UserOrganization and OrganizationConfig in a single query
     statement = (
-        select(Organization)
+        select(Organization, OrganizationConfig)
         .join(UserOrganization)
+        .outerjoin(OrganizationConfig)
         .where(
             UserOrganization.user_id == user_id,
             UserOrganization.role_id == 1,  # Only where the user is admin
+            UserOrganization.org_id == Organization.id,
+            OrganizationConfig.org_id == Organization.id
         )
         .offset((page - 1) * limit)
         .limit(limit)
     )
 
-    # Get organizations where the user is an admin
+    # Execute single query to get all data
     result = db_session.exec(statement)
-    orgs = result.all()
+    org_data = result.all()
 
+    # Process results in memory
     orgsWithConfig = []
-
+    for org, org_config in org_data:
-    for org in orgs:
-
-        # Get org config
-        statement = select(OrganizationConfig).where(
-            OrganizationConfig.org_id == org.id
-        )
-        result = db_session.exec(statement)
-
-        org_config = result.first()
-
         config = OrganizationConfig.model_validate(org_config) if org_config else {}
-
+        org_read = OrganizationRead(**org.model_dump(), config=config)
-        org = OrganizationRead(**org.model_dump(), config=config)
+        orgsWithConfig.append(org_read)
-
-        orgsWithConfig.append(org)
 
     return orgsWithConfig
 
@@ -573,36 +565,30 @@ async def get_orgs_by_user(
     page: int = 1,
     limit: int = 10,
 ) -> list[OrganizationRead]:
-
+    # Join Organization, UserOrganization and OrganizationConfig in a single query
     statement = (
-        select(Organization)
+        select(Organization, OrganizationConfig)
         .join(UserOrganization)
-        .where(UserOrganization.user_id == user_id)
+        .outerjoin(OrganizationConfig)
+        .where(
+            UserOrganization.user_id == user_id,
+            UserOrganization.org_id == Organization.id,
+            OrganizationConfig.org_id == Organization.id
+        )
         .offset((page - 1) * limit)
         .limit(limit)
     )
 
-    # Get organizations where the user is an admin
+    # Execute single query to get all data
     result = db_session.exec(statement)
-    orgs = result.all()
+    org_data = result.all()
 
+    # Process results in memory
     orgsWithConfig = []
-
+    for org, org_config in org_data:
-    for org in orgs:
-
-        # Get org config
-        statement = select(OrganizationConfig).where(
-            OrganizationConfig.org_id == org.id
-        )
-        result = db_session.exec(statement)
-
-        org_config = result.first()
-
         config = OrganizationConfig.model_validate(org_config) if org_config else {}
-
+        org_read = OrganizationRead(**org.model_dump(), config=config)
-        org = OrganizationRead(**org.model_dump(), config=config)
+        orgsWithConfig.append(org_read)
-
-        orgsWithConfig.append(org)
 
     return orgsWithConfig