SQL
Choose a repeatable shortlist
BOTIE
Examples, experiments and workspace controls
Connect a tool's inputs to see what it produces. You can try a branch before connecting it to Result.
Try your own inputs
Use a copy of the example to try your own data. Keep the problem's assumptions in mind, and predict the effect of a change before checking the output. You can also add another branch to compare two ways of doing the calculation.
Context for this challenge
Build the ordering and inspect the complete ranked records before connecting the limit.
The first two stored visits are not necessarily the two longest.
Inspect the component calculation
Order rows by named fields(
Rows: Keep rows passing a comparison(
Rows: Inspection visits
Comparison value: 0
Field to compare: minutes
Comparison: >=
)
Order, for example minutes DESC, inspection_id ASC: minutes DESC, inspection_id ASC
)Examples and results
- Inspection visits
[ { "inspection_id": 101, "asset_id": "P1", "minutes": 30, "finding": "loose" }, { "inspection_id": 102, "asset_id": "P1", "minutes": null, "finding": null }, { "inspection_id": 103, "asset_id": "P2", "minutes": 0, "finding": "clear" }, { "inspection_id": 104, "asset_id": "P3", "minutes": 20, "finding": "clear" }, { "inspection_id": 105, "asset_id": "P2", "minutes": 10, "finding": "loose" }, { "inspection_id": 106, "asset_id": "P1", "minutes": 15, "finding": "loose" } ]- Required result
[ { "inspection_id": 101, "asset_id": "P1", "minutes": 30, "finding": "loose" }, { "inspection_id": 104, "asset_id": "P3", "minutes": 20, "finding": "clear" }, { "inspection_id": 106, "asset_id": "P1", "minutes": 15, "finding": "loose" }, { "inspection_id": 105, "asset_id": "P2", "minutes": 10, "finding": "loose" }, { "inspection_id": 103, "asset_id": "P2", "minutes": 0, "finding": "clear" } ]
Try a fresh construction
This clears this draft, including its undo history. Earlier successful attempts stay recorded. Build again without opening hints to record an independent attempt.
Stuck? Inspect a worked construction
The tools below form one possible solution. You can assemble it, follow its signals, and undo that change to return to your own construction.
Assumptions and test precision
The workshop calculates over small record lists to make the relational operations visible. It is not a SQL parser or query planner. The worksheet runs SQLite and is the authority for SQL behaviour, including types and NULL. Numerical tests allow a difference of 0.001. Lists and structures must also have the right shape.
Your last tested pieces can start the full construction. An existing draft there keeps its own pieces.
Only one duration is known
This check uses the pieces from “Rank the complete candidate population”.
BOTIE
- Inspection visits
[ { "inspection_id": 8, "minutes": null }, { "inspection_id": 9, "minutes": 0 } ]
Use a number, text, or an array matching the requested result. For a matrix, put each row in brackets. Saving your prediction runs your current construction on these inputs and checks the earlier examples too.
Build a construction in the workspace above first. This case will test those pieces.
If three records tie at the boundary, does a limit of two include all three?
Separate a fixed row-count shortlist from an all-ties ranking policy.
The workshop calculates over small record lists to make the relational operations visible. It is not a SQL parser or query planner. The worksheet runs SQLite and is the authority for SQL behaviour, including types and NULL.
Work through the SQL challenges →