当ID相同时获取所有数据的查询

Question

我有一张表可以返回这些结果。

ProcessID AddressID ItemStateID 
22    2   50 
22    3   50 
22    4   50 
22    5   50 
22    6   50 
22    7   60 
22    7   50 
22    8   50 
22    9   50 
22    10   60 
22    10   50 
22    11   50 
22    12   50 

但我想是这样的：

ProcessID AddressID ItemStateID 
22    2   50 
22    3   50 
22    4   50 
22    5   50 
22    6   50 
22    7   60 
22    8   50 
22    9   50 
22    10   60 
22    11   50 
22    12   50 

当AddressID是一样的，我想拿到最高ItemStateID一行...

现在这是查询我目前正在使用：

SELECT DISTINCT 
    ProcessID, 
    AddressID, 
    ItemStateID 
FROM MMResult2 
WHERE ProcessID = 22 AND ItemStateID > 10 
ORDER BY AddressID ASC, ItemStateID DESC 

Answer 1

删除distinct并按您想要的列组 独特。要聚合的最后一列使用max()

SELECT ProcessID, 
     AddressID, 
     max(ItemStateID) as MaxItemStateID 
FROM MMResult2 
WHERE ProcessID = 22 
    AND ItemStateID > 10 
GROUP BY ProcessID, 
     AddressID 
ORDER BY AddressID ASC, 
     max(ItemStateID) DESC 

Answer 2

您可以使用GROUP BY：

SELECT 
    ProcessID, 
    AddressID, 
    MAX(ItemStateID) 
FROM MMResult2 
WHERE ProcessID = 22 AND ItemStateID > 10 
GROUP BY AddressID 

Answer 3

使用GROUP BY和MAX功能。

SELECT DISTINCT ProcessID, AddressID, MAX(ItemStateID) AS HighestItemStateID 
FROM MMResult2 
WHERE ProcessID = 22 AND ItemStateID > 10 
GROUP BY ProcessID, AddressID, 
ORDER BY AddressID ASC, ItemStateID DESC 

Answer 4

SELECT 
    ProcessID, 
    AddressID, 
    MAX(ItemStateID) AS ItemStateID 
FROM MMResult2 
WHERE ProcessID = 22 AND ItemStateID > 10 
GROUP BY ProcessID, AddressID 
ORDER BY AddressID ASC, ItemStateID DESC