按 SQL 中的 2 个不同值分组并过滤

Question

我有table T1

ID Size
A  1
A  2
A  3
B  3
B  4
C  2
C  4

我想按ID分组，过滤每个ID的最小尺寸

期望的结果：

A 1
B 3
C 2

我试过这样做：

SELECT ID, Size
FROM T1
WHERE ID IN (SELECT DISTINCT ID FROM T1)

Answer 1

您需要一个基本的 GROUP BY 查询：

SELECT ID, MIN(Size) AS Size
FROM T1
GROUP BY ID;

Answer 2

SELECT T1.id, MIN(T1.SIZE) AS MinimumSize FROM T1 GROUP BY T1.ID

也许你能找到你的解决方案。

Group by and filter on 2 Distinct values in SQL