MySQL獲取最新日期，相關的最新插入

Question

我有兩個要合並在一起的查詢，因此不必一個接一個地執行，因為在某些情況下，我想更改輸出順序。

第一個查詢，獲取發票狀態。 它會更改以保留日志，但是在99％的時間內，我只需要檢查最新條目即可。 布局如下：

provider_invoice_status_ID，providers_invoice_summary_ID，status_ID，userinfo_ID，providers_invoice_status_date

SELECT providers_invoice_summary_ID
  FROM db_providers_invoice_status
 WHERE status_ID = '$status'
 ORDER BY providers_invoice_status_date DESC

然后根據上述查詢的結果查詢發票表。 布局如下。

provider_invoice_summary_ID，providers_invoice_summary_file，providers_invoice_summary_total，providers_invoice_summary_due，providers_invoice_summary_genic

    SELECT si.providers_invoice_summary_ID
     , providers_invoice_summary_file
     , providers_invoice_summary_total
     , providers_invoice_summary_due
     , providers_invoice_summary_generated
  FROM db_providers_invoice_summary si 
 WHERE providers_invoice_summary_ID = '$invoice_ID';

可能嘗試合並查詢，結果是：

SELECT si.providers_invoice_summary_ID
     , providers_invoice_summary_file
     , providers_invoice_summary_total
     , providers_invoice_summary_due
     , providers_invoice_summary_generated
     , s.status_ID 
  FROM db_providers_invoice_summary si, db_providers_invoice_status s
 WHERE status_ID = ( SELECT status_ID
                   FROM db_providers_invoice_status
                  WHERE providers_invoice_summary_ID = si.providers_invoice_summary_ID 
                    AND status_ID = 7  
                  ORDER 
                     BY providers_invoice_status_date DESC 
                  LIMIT 1)

但是，它從status_ID = 7的狀態記錄表中提取所有結果，因此不能完全獲取最新的插入內容（此后此狀態可能已更改為8，因此不希望使用invoice_ID）。 我嘗試使用ORDER BY，但是它僅對所有結果進行排序，而不是我所追求的子集。

任何幫助，將不勝感激。 希望對閱讀它的人來說這很清楚，我知道它很復雜。

編輯數據：

發票表：

providers_invoice_summary_ID providers_invoice_summary_file providers_invoice_summary_total providers_invoice_summary_due providers_invoice_summary_generated
----------------------------------------------------------------------------------------------------------------------------------------------------------
           4                |        ../blah/blah.jpg      |            245.63       |           2014-04-20               |           2014-03-14
           5                |        ../blah/blah.jpg      |            456.89       |           2014-04-20               |           2014-03-12
           6                |        ../blah/blah.jpg      |            125.36       |           2014-04-24               |           2014-03-12    

狀態表：

providers_invoice_status_ID providers_invoice_summary_ID status_ID userinfo_ID providers_invoice_Status_date
------------------------------------------------------------------------------------------------------------
               4           |              4             |   7     |      7    |   2014-03-14 10:19:41
               5           |              5             |   7     |      7    |   2014-03-12 10:22:41
               6           |              6             |   7     |      7    |   2014-03-24 10:15:38
               7           |              5             |   8     |      7    |   2014-03-26 11:15:14

我希望能從這些數據中獲得2張發票，因為目前有2張發票的最新狀態設置為7張。希望這可以進一步澄清。

Answer 1

這是兩個查詢的組合版本。 我創建了一個子查詢來選擇狀態與輸入狀態ID（例如7）匹配的發票。 反過來，狀態ID是使用最新狀態日期從子查詢中獲取的。

更新查詢 ：

SELECT 
 si.providers_invoice_summary_ID
 , si.providers_invoice_summary_file
 , si.providers_invoice_summary_total
 , si.providers_invoice_summary_due
 , si.providers_invoice_summary_generated
 , invoice_status.status_ID 
FROM 
  db_providers_invoice_summary si, 
  (SELECT t1.providers_invoice_summary_ID as providers_invoice_summary_ID
      , t1.status_id as status_id
   FROM db_providers_invoice_status t1
  LEFT JOIN db_providers_invoice_status t2 ON t1.providers_invoice_summary_ID = t2.providers_invoice_summary_ID AND t1.providers_invoice_Status_date < t2.providers_invoice_Status_date
WHERE t2.providers_invoice_summary_ID IS NULL
  AND t1.status_id = 7
   ) invoice_status
WHERE SI.PROVIDERS_INVOICE_SUMMARY_ID = invoice_status.PROVIDERS_INVOICE_SUMMARY_ID

請同時查看sql小提琴以獲取演示。

參考文獻 ：

MySQL：行包含某個列的分組最大值