Question

我的查询返回每个用户标识的最新条目，但我需要它返回每个用户标识和任务名称的最新条目。我试图使用group by，但是我收到了一个错误。有什么我做错了吗？谢谢！

SELECT UserId, TaskName, First, Last, email, ValueDate, Analysis
FROM (SELECT UserId, TaskName, First, Last, 
email, ValueDate, Analysis,
ROW_NUMBER() OVER(PARTITION BY UserID
ORDER BY ValueDate DESC) AS rk
FROM MyTable) AS L
WHERE rk = 1

Answer 1

您应该将 PARTITION BY UserID 替换为 PARTITION BY UserID，TaskName ：

SELECT UserId, TaskName, First, Last, email, ValueDate, Analysis
FROM (SELECT UserId, TaskName, First, Last, 
email, ValueDate, Analysis,
ROW_NUMBER() OVER(PARTITION BY UserID, TaskName
ORDER BY ValueDate DESC) AS rk
FROM MyTable) AS L
WHERE rk = 1

Answer 2

如果没有一些数据来测试和表格结构，我只能假设你真正想要实现的目标，但它可能是这样的：

SELECT UserId, TaskName, First, Last, email, max(ValueDate), Analysis
FROM MyTable
GROUP BY UserId, TaskName, First, Last, email, Analysis
ORDER BY MAX(ValueDate) DESC

SQL Server over query

2 个答案: