MySQL - HAVING

什麼是HAVING

HAVING 是 SQL 中用於指定對通過 GROUP BY 聚合的結果集進行過濾的條件的子句

它的作用類似於 WHERE 子句, 但 WHERE 過濾的是行, 而 HAVING 過濾的是聚合結果

範例

INPUT:
SELECT name, score
FROM grades

OUTPUT:
| name   | score  |
|--------|--------|
| Jasper | 100    |
| David  | 60     |
| Alice  | 64     |
| David  | 87     |
| Alice  | 98     |
| Jasper | 100    |

INPUT:
SELECT name, SUM(score)
FROM grades
GROUP BY name
HAVING SUM(score) > 150;

OUTPUT:
| name   | score  |
|--------|--------|
| Jasper | 200    |
| Alice  | 162    |