sql - INNER JOIN & MAX 问题

Question

我有下表，我们在其中存储项目计划：

ID    PROJECT_NAME   MILESTONE_NAME

所有里程碑都以数字开头，例如“0.1 - 里程碑描述”。

我想检索按项目订购的 MAX MILESTONE_NAME。

我使用了以下代码，但它不起作用......

SELECT Sheet1.[PROJECT_NAME], MAX(Sheet1.[MILESTONE_NAME])
FROM Sheet1 INNER JOIN Sheet1 AS Sheet1_1 ON (Sheet1.[PROJECT_NAME] = Sheet1_1.[PROJECT_NAME]) AND (Sheet1.[MILESTONE_NAME] = Sheet1_1.[MILESTONE_NAME])
ORDER BY Sheet1.[PROJECT_NAME]

它说 PROJECT_NAME 不在聚合函数中。

你们知道我应该如何前进吗？

谢谢！

Answer 1

你必须GROUP BY Sheet1.[PROJECT_NAME]。

尝试 ：

SELECT Sheet1.[PROJECT_NAME], MAX(Sheet1.[MILESTONE_NAME])
FROM Sheet1
    INNER JOIN Sheet1 AS Sheet1_1 ON (Sheet1.[PROJECT_NAME] = Sheet1_1.[PROJECT_NAME])
        AND (Sheet1.[MILESTONE_NAME] = Sheet1_1.[MILESTONE_NAME])
GROUP BY Sheet1.[PROJECT_NAME]
ORDER BY Sheet1.[PROJECT_NAME]

Answer 2

添加到查询：

GROUP BY Sheet1.[PROJECT_NAME];