Filter, Order, and Limit Results
Use filter_by, order_by, and pagination.
Filter, Order, and Limit Results is a free Flask Academy lesson on CoddyKit — lesson 2 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Flask Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Narrow Results with filter_by
Use filter_by() with keyword arguments to keep only rows that match a column exactly. It reads almost like English. 🎯
admins = User.query.filter_by(role="admin").all()More Power with filter
When you need comparisons, reach for filter() and full column expressions instead of plain equality.
adults = User.query.filter(User.age >= 18).all()Combine Conditions
Pass several expressions to filter() and they join with AND, so every condition must hold for a row to match.
q = User.query.filter(User.age >= 18, User.active == True)OR Conditions
For an either-or match, wrap conditions in or_() so a row qualifies when any one of them is true.
from sqlalchemy import or_
q = User.query.filter(or_(User.age < 18, User.vip))Sort with order_by
Use order_by() to sort results by a column. By default rows come back in ascending order.
users = User.query.order_by(User.name).all()Newest First with desc
Wrap a column in desc() to flip the sort and put the largest or latest values at the top.
posts = Post.query.order_by(Post.created.desc()).all()Cap the Count with limit
Add limit() to fetch only the first N rows. It keeps responses small and queries fast.
top = Post.query.order_by(Post.score.desc()).limit(5).all()Skip Rows with offset
Use offset() to skip a number of rows before returning. Combined with limit, it gives you simple paging.
page2 = Post.query.limit(10).offset(10).all()Real Pagination with paginate
Flask-SQLAlchemy bundles paging into paginate(), which returns items plus handy page metadata in one call.
p = Post.query.paginate(page=2, per_page=10)Chain It All Together
Filter, order, and limit chain fluently, and nothing runs until you finish with all or first.
q = Post.query.filter_by(public=True).order_by(Post.id.desc()).limit(3)Order Matters for Limits
Always pair limit() with order_by. Without a sort, which rows you get back is unpredictable.
Quick Check
You want the three highest-scoring posts. Which clause makes the score the top result?
Recap: Shaping Results
You can now filter, sort with order_by and desc, and trim output with limit, offset, and paginate. Powerful reads unlocked! 🚀
Frequently asked questions
Is the “Filter, Order, and Limit Results” lesson free?
Yes — the full text of “Filter, Order, and Limit Results” is free to read here on the web, and the Flask Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Flask Academy course, upgrade to CoddyKit PRO.
What will I learn in “Filter, Order, and Limit Results”?
Use filter_by, order_by, and pagination. You practise Flask Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Flask Academy?
No prior experience is required. Flask Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 2 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Filter, Order, and Limit Results” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Flask Academy lesson?
Yes. Every Flask Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Fetch Rows with query and get
- Filter, Order, and Limit Results
- Define Relationships and Foreign Keys
- Joins and Lazy vs Eager Loading