Chefs Who Tasted Their Own Dish
Problem
Table: `Tastings`
```text
+------------+---------+
| Column | Type |
+------------+---------+
| dish_id | int |
| chef_id | int |
| taster_id | int |
| taste_day | date |
+------------+---------+
There is no single-column primary key. Each row means taster_id tasted the
dish dish_id, which was created by chef_id, on taste_day.
```
Find every chef who tasted at least one of their own dishes (the chef and the
taster are the same person). Return one row per such chef. Use the column
heading `id` and sort the result by `id` in ascending order.
**Example**
```text
Tastings:
+---------+---------+-----------+------------+
| dish_id | chef_id | taster_id | taste_day |
+---------+---------+-----------+------------+
| 1 | 5 | 5 | 2024-01-01 |
| 2 | 5 | 7 | 2024-01-01 |
| 3 | 8 | 8 | 2024-01-02 |
| 4 | 9 | 5 | 2024-01-03 |
+---------+---------+-----------+------------+
Output:
+----+
| id |
+----+
| 5 |
| 8 |
+----+
```
Chef 5 tasted dish 1 (their own) and chef 8 tasted dish 3 (their own).
Tables
Example rows — the live problem includes the full dataset.
| dish_id | chef_id | taster_id | taste_day |
|---|---|---|---|
| 1 | 5 | 5 | 2024-01-01 |
| 2 | 5 | 7 | 2024-01-01 |
| 3 | 8 | 8 | 2024-01-02 |
Expected output
Your answer should return 2 rows with the columns id.
Starter code (SQL)
SELECT *
FROM Tastings;Solve this SQL question free
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Solution & explanation
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