SQL識別雲ID的

Question

我正在分析一個數據集。表有3列：

-CLOUD_ID (ID Field) example: 121312 

-CURRENT_Action (Textfield) example: Started 

-MIN_STARTDATE (Date) example: 2016-04-20 17:03:58.633 

我需要確定Cloud_ID的不具備Current_Action「已刪除」作爲最低MIN_Startdate。

Answer 1

一個sligtly不同的方法，請比較PERF：

with x as (select *, row_number() over(partition by cloud_id order by min_startdate) rn from @t) 
select cloud_id from x where rn = 1 and current_action <> 'deleted' 

Answer 2

您可以使用窗口函數：

select distinct cloud_id 
from (select t.*, 
      min(min_startdate) over (partition by cloud_id) as min_min_startdate 
     from t 
    ) t 
where min_startdate = min_min_startdate and 
     Current_Action <> 'Deleted'; 

注：這是假定Current_Action不是NULL，但很容易被包含在邏輯。