Sql LeftJoin中MAX（）值的子查询

我在SQL Server中有这个查询，我想知道它是否可以缩短

我对所有列进行了一个子查询（带有GROUPBY），以获取来自表左联接的3个日期的MAX（）值

我想我不能没有子查询来获取3个日期的MAX（）

SELECT otherCol1
    ,otherCol2 
    ,MAX(UnsubscribedDate) AS UnsubscribedDate
    ,MAX(OpenedDate) AS OpenedDate
    ,MAX(ClickedDate) AS ClickedDate
FROM (
    SELECT otherCol1
        ,otherCol2
        ,tu.JoinDate AS UnsubscribedDate
        ,trkOp.Clicktime AS OpenedDate
        ,trkRes.Clicktime AS ClickedDate
    FROM v_members_email_occurrence vmec
    LEFT JOIN tracking_unsubscribed tu WITH (NOLOCK) ON tu.ReportId = vmec.SendingId
    LEFT JOIN tracking_opened trkOp WITH (NOLOCK) ON trkOp.ReportId = vmec.SendingId
    LEFT JOIN tracking_result trkRes WITH (NOLOCK) ON trkRes.ReportId = vmec.SendingId
    WHERE vmec.MemberId = @MemberId
    ) AS Result
GROUP BY otherCol1
        ,otherCol2

---

您可以不使用子查询进行聚合：

SELECT otherCol1
    ,otherCol2
    ,MAX(tu.JoinDate) AS UnsubscribedDate
    ,MAX(trkOp.Clicktime) AS OpenedDate
    ,MAX(trkRes.Clicktime) AS ClickedDate
FROM v_members_email_occurrence vmec
LEFT JOIN tracking_unsubscribed tu WITH (NOLOCK) ON tu.ReportId = vmec.SendingId
LEFT JOIN tracking_opened trkOp WITH (NOLOCK) ON trkOp.ReportId = vmec.SendingId
LEFT JOIN tracking_result trkRes WITH (NOLOCK) ON trkRes.ReportId = vmec.SendingId
WHERE vmec.MemberId = @MemberId
GROUP BY otherCol1
        ,otherCol2

---

您可以不使用子查询进行聚合：

SELECT otherCol1
    ,otherCol2
    ,MAX(tu.JoinDate) AS UnsubscribedDate
    ,MAX(trkOp.Clicktime) AS OpenedDate
    ,MAX(trkRes.Clicktime) AS ClickedDate
FROM v_members_email_occurrence vmec
LEFT JOIN tracking_unsubscribed tu WITH (NOLOCK) ON tu.ReportId = vmec.SendingId
LEFT JOIN tracking_opened trkOp WITH (NOLOCK) ON trkOp.ReportId = vmec.SendingId
LEFT JOIN tracking_result trkRes WITH (NOLOCK) ON trkRes.ReportId = vmec.SendingId
WHERE vmec.MemberId = @MemberId
GROUP BY otherCol1
        ,otherCol2