Question

我有这个样本表：

id    branch    branch_running_no
1      1         5
2      1         10
3      2         5
4      2         10
5      3         5
6      3         10
7      4         5
8      4         10
9      5         5
10     5         10

使用此查询，我可以获取每个分支列的max branch_running_no，但我还想包含max branch_running_no的列id。

SELECT branch, MAX(branch_running_no) from table1 GROUP BY branch order by branch;

我能够实现：

branch    max
1         10
2         10
3         10
4         10
5         10

但我需要：

id    branch    max
2     1         10
4     2         10
6     3         10
8     4         10
10    5         10

Answer 1

SELECT id
     ,branch
     ,branch_running_no
FROM (
    SELECT id
           ,branch
           ,branch_running_no
           ,row_number() OVER (PARTITION BY branch ORDER BY branch_running_no DESC) rn
    FROM t
    ) t
WHERE rn = 1

或

SELECT distinct on(branch) id,branch, MAX(branch_running_no) from t GROUP BY id,branch order by branch,3 desc;

Answer 2

SELECT id，branch，MAX（branch_running_no）来自table1 GROUP BY id，分支顺序by id，branch;

postgres选择查询3列，最大值

2 个答案: