Which classes?
#016BasicSELECT3 min
A new teacher wants to know which classes the school has. From the students table, pick the class column, with each class appearing only once.
The tablesstudents| id | name | class | age | city |
|---|
| 1 | Amy | 1A | 12 | Leeds |
| 2 | Ben | 1A | 13 | York |
| 3 | Cara | 1B | 12 | NULL |
| 4 | Dan | 1B | 14 | Leeds |
| 5 | Eva | 1A | 12 | Hull |
| 6 | Finn | 1C | 13 | NULL |
| 7 | Gus | 1C | 12 | York |
7 rows
scores| id | student_id | subject | score |
|---|
| 1 | 1 | math | 92 |
| 2 | 1 | art | 78 |
| 3 | 2 | math | 65 |
| 4 | 2 | art | 88 |
| 5 | 3 | math | 74 |
| 6 | 4 | math | 55 |
| 7 | 4 | art | 90 |
| 8 | 5 | math | 81 |
| 9 | 5 | art | NULL |
| 10 | 7 | math | 99 |
10 rows
students| id | name | class | age | city |
|---|
| 1 | Amy | 1A | 12 | Leeds |
| 2 | Ben | 1A | 13 | York |
| 3 | Cara | 1B | 12 | NULL |
| 4 | Dan | 1B | 14 | Leeds |
| 5 | Eva | 1A | 12 | Hull |
| 6 | Finn | 1C | 13 | NULL |
| 7 | Gus | 1C | 12 | York |
7 rows
scores| id | student_id | subject | score |
|---|
| 1 | 1 | math | 92 |
| 2 | 1 | art | 78 |
| 3 | 2 | math | 65 |
| 4 | 2 | art | 88 |
| 5 | 3 | math | 74 |
| 6 | 4 | math | 55 |
| 7 | 4 | art | 90 |
| 8 | 5 | math | 81 |
| 9 | 5 | art | NULL |
| 10 | 7 | math | 99 |
10 rows
query.sql
-- your code here: one word after SELECT that drops the repeats
SELECT class
FROM students;
Ctrl + Enter runs too
Result
Run shows what your query gives. When it looks right, Submit.