Question

我有一个名为machineStatus的表：

ID  Successfiles totaldata Backupsessiontime
> 1 3   988   1256637314
> 2 21   323   1256551419
> 3 8   23   1256642968
> 4 94   424   1256642968
> 1 42   324   1256810937
> 1 0   433   1256642968

现在我想在ID中对成功文件和总数据进行总结，但只显示最新的Backupsessiontime。我可以单独做但不能一起做。任何建议????

单独这样做：

获得总和：

select ID, sum(NumOfSuccessFiles), sum(TotalData)
from MachineStat
 group by ID;

获取最新消息：

With idT as (
select ID
from MachineStat
group by ID

) 
select applyT.* 
from idT p
CROSS APPLY (
select top 1 ID,BackupSessionTime from MachineStat where eID=p.ID   
order by MachineID desc
) as applyT

Answer 1

您可以使用适合您需要的聚合函数：

select
    ID,
    sum(NumOfSuccessFiles) TotalNumOfSuccessFiles,
    sum(TotalData) TotalData,
    max(Backupsessiontime) LastBackupsessiontime
from
    MachineStat ms
group by
    ID

如果您需要更复杂的排序逻辑，也可以在主查询中使用子查询。

select
    ID,
    sum(NumOfSuccessFiles) TotalNumOfSuccessFiles,
    sum(TotalData) TotalData,
    (select top 1 Backupsessiontime from MachineStat where ID = ms.ID order by ...) LastBackupsessiontime
from
    MachineStat ms
group by
    ID

Answer 2

看起来你想要做

select ID, sum(NumOfSuccessFiles), sum(TotalData), max(Backupsessiontime) from MachineStat group by ID;

Answer 3

Max（BackupSessionTime）？

SQL查询以获取总和和最新条目

3 个答案: