Distinguish grouped and row-level results
See this course’s project requirements
A reproducible SQLite attendance analysis with per-session rank, running totals and prior-period changes that retains every original row.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- A grouped-versus-windowed result choice.
- An independent session sequence with deterministic ordering.
- A week rank record 3,1,1 with declared tie behavior.
- Running-total rows A 8,20,32 and B 6,15.
- A row-comparison record with honest missing-baseline handling.
- A reproducible window-analysis packet.
Review and revise
Use these criteria to check your work and choose what to improve.
- The implementation or declared simulation follows the supplied contract and retains inspectable original inputs.
- Normal, boundary and rejected cases are recorded with expected versus observed results.
- The changed case has a correct explanation and does not rely on hidden state.
- The project includes source, outputs, instructions and honest tool, privacy and verification limits.
Want more background?
The idea in everyday life
Visits are A week 1=8, week 2=12, week 3=12; B week 1=6, week 2=9. The fixture has five records, two sessions.
GROUP BY collapses records to summary rows. A window calculation retains original rows while adding context, so you can see each week and its group comparison.
Distinguish grouped and row-level results — original worked practice
GROUP BY collapses records to summary rows. A window calculation retains original rows while adding context, so you can see each week and its group comparison.
Visits are A week 1=8, week 2=12, week 3=12; B week 1=6, week 2=9. The fixture has five records, two sessions.
1. Step 1
List five original rows.
You should see: A has 3 rows; B has 2.
This keeps the rule and its observable result together.
2. Step 2
Calculate grouped totals.
You should see: A 32 and B 15 would be two summary rows.
This keeps the rule and its observable result together.
3. Step 3
Compare with windowed rows.
You should see: All five remain and gain computed columns.
This keeps the rule and its observable result together.
4. Step 4
Record which form fits week-by-week review.
You should see: A grouped-versus-windowed result choice.
This keeps the rule and its observable result together.
What to finish
A grouped-versus-windowed result choice.
Watch for this
Replacing row-level evidence with GROUP BY totals when the report still needs each attendance row.
How can I tell I understand it?
Explain and demonstrate the required distinction: GROUP BY collapses records to summary rows. A window calculation retains original rows while adding context, so you can see each week and its group comparison. Show a changed input and the expected result without weakening this contract.
Quick knowledge check
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Source & access notes · checked 2026-10-01
Relevant documented module/API behavior inspected during expansion authoring; actual execution evidence is recorded separately. No grant eligibility is established.
Access: Official page retrieved with the web reader on 2026-10-01. Documentation reading does not certify execution in every native tool or browser.
Reuse: Original local practice files, fictional data, worked examples and questions. Concepts paraphrased and linked; source exercises are not copied.
Source & access notes · checked 2026-10-01
Relevant documented module/API behavior inspected during expansion authoring; actual execution evidence is recorded separately. No grant eligibility is established.
Access: Official page retrieved with the web reader on 2026-10-01. Documentation reading does not certify execution in every native tool or browser.
Reuse: Original local practice files, fictional data, worked examples and questions. Concepts paraphrased and linked; source exercises are not copied.
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