Mode disclosure
All modes use one coherent workspace; only disclosure and guidance change. Practice mode uses a concise prompt, normal schema, optional hints, and the same local Run and Check pipeline.
Row-Level Expressions / write query
M04-A03 - Edit - add a discount calculation with explicit parentheses
M04-A03 - Edit - add a discount calculation with explicit parentheses. Create arithmetic and text-derived values while preserving input row grain.
- Result grain
- one discounted price per product row
- Exact columns
- product_id; discounted_price
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
Build row-level numeric and text expressions while preserving input row grain, explicit aliases, and clear operator precedence.
Row-Level Expressions / write query
One-sentence task
M04-A03 - Edit - add a discount calculation with explicit parentheses. Create arithmetic and text-derived values while preserving input row grain.
Practice mode disclosure
Concise prompt, normal schema help, optional hints, and the same checker workspace are available.
Structured output contract
- Result grain
- one discounted price per product row
- Exact columns
- product_id; discounted_price
- Source population
- Use the prompt setup plus FROM, JOIN, WHERE, and subquery predicates as the source population. Visible rows are only examples.
- Grouping
- Do not collapse rows unless the contract explicitly asks for aggregation, distinct tuples, or set semantics.
- Ordering
- order by product_id
- Validation
- select-only; hidden deterministic variants.
Relevant tables
Time and difficulty
- Estimated time
- 6 minutes
- Difficulty
- 1/5
Objective and concepts
Practice mode keeps the prompt concise; open hints only if you choose guided help.
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
- Do not invent zero rows unless the contract asks for preserved parents, missing entities, or complete periods.
- Numeric tolerance
- Round only at the requested final stage; hidden checks use the contract precision rather than visible formatting luck.
Opened hints
No hints opened yet.