Vlak 10.5 SQL-probleemoplossingsboek
Daar word tabelle gegee:
| id | first_name | last_name | dob | department_id |
|---|---|---|---|---|
| 1 | John | Smith | 1987-12-12 | 4 |
| 2 | Alex | Cooper | 1999-02-20 | 3 |
| 3 | Agata | Leyla | 1970-01-30 | 1 |
| 4 | Ivan | Ivanov | 1994-05-31 | 1 |
| 5 | Peter | Petrov | 1991-08-24 | 3 |
| 6 | Karl | Benz | 1988-01-25 | 4 |
| 7 | Joe | Sparrow | 1990-11-29 | 2 |
| 8 | John | Doe | 1992-12-24 | 2 |
| id | name | registration_date |
|---|---|---|
| 1 | Ruby | 2005-12-30 |
| 2 | PHP | 2000-12-12 |
| 3 | Vue.js | 2015-07-31 |
| 4 | React | 2014-05-31 |
| id | employee_id | amount | date |
|---|---|---|---|
| 1 | 7 | 3500 | 2023-12-12 |
| 2 | 8 | 3000 | 2023-11-10 |
| 3 | 1 | 3200 | 2023-11-11 |
| 2 | 2 | 4700 | 2023-10-12 |
| 5 | 4 | 5500 | 2023-12-07 |
| 6 | 3 | 5600 | 2023-12-10 |
| 8 | 1 | 4000 | 2023-12-11 |
| 7 | 2 | 2100 | 2023-10-11 |
Los die volgende probleme vir hulle op:
Vind die gemiddelde salarisgrootte in elke afdeling vir 'Desember' 2023 en gee inligting oor afdelings uit waar die gemiddelde salarisgrootte 'n sekere drempel oorskry.
