需要幫助查詢數據庫以顯示最新版本

Question

我使用名爲Page的表格處理mysql數據庫。有沒有什麼辦法可以從每個頁面中提取最新版本？

ID  Page Title  Version 
0001 Homepage  1 
0002 Homepage  2 
0003 Homepage  3 
0004 Contact   1 
0005 Contact   2 
0006 Basket   1 
0007 Basket   2 
0008 Basket   3 
0009 Basket   4 

我需要什麼：

ID  Page Title  Version 
0003 Homepage  3 
0005 Contact   2 
0009 Basket   4 

Answer 1

您可以使用MAX和GROUP BY，具體如下：

SELECT MAX(ID) 
     ,PageTtile 
     ,MAX(version) 
    FROM Page 
    GROUP BY PageTitle 

Answer 2

你也可以使用ROW_NUMBER（）如下

SELECT * FROM (
SELECT Row_Number() over (partition by Title order by Version DESC) As rn, Page, Title, Version FROM Page) a 
where rn = 1 

Answer 3

嘗試此查詢 -

SELECT t1.* FROM tbl t1 
JOIN (SELECT PageTitle, MAX(Version) Version FROM tbl GROUP BY PageTitle) t2 
    ON t1.PageTitle = t2.PageTitle AND t1.Version = t2.Version; 

輸出：

3 Homepage 3 
5 Contact 2 
9 Basket 4