Informix子​​查詢 - 如何正確執行它們

Question

我正在研究一個Informix查詢，它將提供1）給我一個呼叫中心代理列表和2）給我他們最近的狀態。我有一個查詢可以完成我所需要的任何事情;

select b.resourcename, b.extension, a.eventtype 
from agentstatedetail as a, resource as b, team as c 
where date (eventdatetime) = TODAY 
    and (a.agentid = b.resourceid) 
    and (b.assignedteamid = c.teamid) 
    and (c.teamname like 'Team Name %') 
group by b.resourcename, b.extension, a.eventtype 
order by resourcename asc 

然而，這會給我的「事件類型」（事件類型顯示了美國代理人是在給定時間）的完整記錄。我試圖只拉最近的狀態。所以，我相信我需要對這個主查詢做一個子查詢，聲明類似於「如果主查詢的輸出在這個子查詢中找到，那麼保留它」。子查詢看起來像這樣;

select a.agentid, b.resourcename, c.teamname, max(a.eventdatetime) 
from agentstatedetail as a, resource as b, team as c 
where date (eventdatetime) = TODAY 
    and a.agentid = b.resourceid 
    and b.assignedteamid = c.teamid 
    and c.teamname like 'Team Name %' 
group by a.agentid, b.resourcename, c.teamname 

這個子查詢本身幾乎是我需要的所有東西，但它沒有事件類型。這個查詢如何工作？

這是我通常寫入子查詢但不能在Informix中工作的格式;

select m.agentid, m.resourcename, m.teamname, a2.eventtype 
from (
    select a.agentid,b.resourcename,c.teamname,max(a.eventdatetime) as maxtdate 
    from agentstatedetail as a 
    inner join resource as b on a.agentid = b.resourceid 
    inner join team as c on b.assignedteamid = c.teamid 
    where date (eventdatetime) = TODAY 
    and c.teamname like 'Team Name %' 
    group by a.agentid, b.resourcename, c.teamname 
) m 
inner join agentstatedetail a2 
    on a2.agentid = m.agentid and a2.eventdatetime = m.maxtdate 

我對你想要的列有點糊塗：

select a.agentid, b.resourcename, c.teamname, max(a.eventdatetime) as eventdatetime, a.eventtype from agentstatedetail as a, resource as b, team as c where date(eventdatetime) = TODAY and a.agentid=b.resourceid and b.assignedteamid=c.teamid and c.teamname like 'ITS %' and where a.eventdatetime in (select a.agentid, b.resourcename, c.teamname, max(a.eventdatetime) from agentstatedetail as a, resource as b, team as c where date(eventdatetime) = TODAY and a.agentid=b.resourceid and b.assignedteamid=c.teamid and c.teamname like 'Team Name %' group by a.agentid, b.resourcename, c.teamname) group by a.agentid, b.resourcename, c.teamname, a.eventtype order by max(a.eventdatetime) desc 

Answer 1

嘗試做內與子查詢和agentstatedetail上的agentId和你發現這是最大日加入最後看看。如果這些不是，你將不得不在內部和外部查詢中改變它們。