Mode disclosure
All modes use one coherent workspace; only disclosure and guidance change. Review mode hides concept labels until submission, keeps a due counter visible, and lets you Skip for Later without losing work.
Workspace Orientation and First Run / predict result
RA-A01 - Write a two-column projection with exact aliases on an unfamiliar table
RA-A01 - Write a two-column projection with exact aliases on an unfamiliar table. Use the product without interface uncertainty; run, edit, check, and recover a first query.
- Result grain
- one row per customer
- Exact columns
- customer_id; customer_name; completed_orders
SQL editor shortcuts: Ctrl or Command Enter runs the query, Ctrl or Command Shift Enter checks it, Alt H opens the next hint, Ctrl or Command slash toggles a line comment, Ctrl or Command Shift F formats the SQL, and Escape closes transient UI.
Cursor at line 1, column 1.
Scenario
Retrieve the skill without relying on the lesson label.
Review mode / concept labels hidden until submission
One-sentence task
RA-A01 - Write a two-column projection with exact aliases on an unfamiliar table. Use the product without interface uncertainty; run, edit, check, and recover a first query.
Review mode disclosure
Concept labels hidden until submission. Use the due counter and Skip for Later without losing the draft.
Structured output contract
- Result grain
- one row per customer
- Exact columns
- customer_id; customer_name; completed_orders
- Source population
- Use the prompt setup plus FROM, JOIN, WHERE, and subquery predicates as the source population. Visible rows are only examples.
- Grouping
- Group only at the requested output grain: one row per customer.
- Ordering
- count completed orders only; order by completed_orders desc then customer_id
- Validation
- select-only; hidden deterministic variants.
Relevant tables
Time and difficulty
- Estimated time
- 4 minutes
- Difficulty
- 2/5
Objective and concepts
Concept labels are hidden until submission so retrieval stays honest.
Assumptions, dialect notes, and common traps
- Duplicate policy
- Preserve duplicate facts unless the prompt explicitly asks for distinct tuples or set semantics.
- Null policy
- Preserve NULL, empty string, zero, and false as distinct values unless the contract says to display a fallback.
- Tie-breakers
- Use every ordering rule in the contract and end tied business metrics with deterministic secondary keys when needed.
- Zero-related entities
- Preserve requested zero-related, no-match, or complete-period entities and make display fallback explicit.
- Numeric tolerance
- Use exact semantic comparison unless the activity explicitly declares a numeric tolerance.
Opened hints
Hints are disabled during active review or challenge assessment and become available after submission or outside assessment mode.