dcf.cymru stimulus sheet · Computer Science · Year 9
This is one big spreadsheet, kept by hand. Your job in the lesson is to work out why it keeps going wrong and redesign it as a proper database.
Print one per pair. It is deliberately messy. Pupils do not have to fix the data — they have to spot the problems and design a better structure on the worksheet. No computers are needed.
"Every time a pupil borrows a Chromebook we add a row. It is up to 900 rows now. Two people type in the names, the dates are in whatever format the typist likes, and last week we could not tell whether asset CB-0042 was out with one pupil or three. When a pupil changes form group we have to hunt through the whole sheet."
| No. | Pupil name | Form | Pupil DOB | Asset tag | Model | Replace cost | Out | Due | Back | Charger? |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Elin Prys | 9B | 12/03/2011 | CB-0042 | Acer Chromebook 314 | £215.00 | 15/09/2025 | 29/09/2025 | 26/09/2025 | yes |
| 2 | Rhys Morgan-Hughes | 9A | 02/11/2010 | CB-0017 | Acer Chromebook 314 | £215.00 | 15/09/2025 | 29/09/2025 | 30/09/2025 | yes |
| 3 | elin prys | 9B | 12/03/2011 | CB-0108 | HP Chromebook 11 G9 | £189.99 | 1st Oct | 15th Oct | no | |
| 4 | Seren Bowen | 9C | 24/07/2011 | CB-0042 | Acer Chromebook 314 | £215 | 02/10/2025 | 16/10/2025 | 14/10/2025 | y |
| 5 | Rhys Morgan Hughes | 9A | 02/11/2010 | CB-0042 | Acer Chromebok 314 | £215.00 | 02/10/2025 | 16/10/2025 | 09/10/2025 | yes |
| 6 | Osian Lloyd | 9B | 30/01/2011 | CB-0091 | Lenovo 300e Chromebook | £232.50 | 06/10/2025 | 20/10/2025 | 20/10/2025 | yes |
| 7 | Seren Bowen | 9D | 24/07/2011 | CB-0017 | Acer Chromebook 314 | £215.00 | 07/10/2025 | 21/10/2025 | no | |
| 8 | Cadi Edwards | 9A | 18/05/2011 | CB-0108 | HP Chromebook 11 G9 | £189.99 | 20/10/2025 | 03/11/2025 | 03/11/2025 | yes |
| 9 | Osian Lloyd | 9B | 30/01/2011 | CB-0091 | Lenovo 300e Chromebook | £232.50 | 05/11/2025 | 19/11/2025 | yes | |
| 10 | Ffion Davies | 9C | 09/09/2011 | CB-0055 | Acer Chromebook 314 | £215.00 | 05/11/2025 | 19/11/2025 | 18/11/2025 | Y |
Pick the narrowest type that fits the data. A date stored as text cannot be sorted or subtracted.
| Type | Holds | Example value |
|---|---|---|
| INTEGER | Whole numbers, including ID numbers | 1042 |
| VARCHAR(n) | Text up to n characters | VARCHAR(40) — "Lenovo 300e Chromebook" |
| CHAR(n) | Text that is always exactly n characters | CHAR(7) — "CB-0042" |
| DATE | A calendar date, sortable and subtractable | 2025-10-02 |
| DECIMAL(p,s) | Exact money, p digits with s after the point | DECIMAL(7,2) — 215.00 |
| BOOLEAN | True or false only | TRUE |