GROUP BY忽略属性 [英] GROUP BY ignoring an attribute

问题描述

例如，我有这张桌子:

itemgroup |描述|价格
A，A，10
A，B，12
A，C，14
B，g，11
B，h，16

itemgroup | description | price
A, a, 10
A, b, 12
A, c, 14
B, g, 11
B, h, 16

现在我要像这样在一组中选择价格最高的行:

now i want to select the rows with the highest price in one group like this:

A，C，14
B，h，16

A, c, 14
B, h, 16

SQL查询(功能齐全)可以使我接近以下位置:

The SQL query (is fully functional) wich gets me near this is:

SELECT itemgroup, MAX( price ) 
FROM table
GROUP BY itemgroup

A，14岁
B，16

A, 14
B, 16

通过尝试此操作，我收到不是GROUP BY表达式"错误:

By trying this I get an "not a GROUP BY expression"-error:

SELECT itemgroup, description, MAX( price ) 
FROM table
GROUP BY itemgroup

我需要类似以下的伪查询:

I need something like this pseudo query:

SELECT itemgroup, IGNORE( description), MAX( price ) 
FROM table
GROUP BY itemgroup

我希望我能解释我的小问题.

I hope i could explain my little problem.

推荐答案

我通常会做类似的事情:

I normally end up doing something like:

SELECT t1.itemgroup, t1.description, t1.price
FROM table t1, 
    (SELECT itemgroup, MAX( price ) as price
     FROM table
     GROUP BY itemgroup) t2
WHERE t1.itemgroup = t2.itemgroup
AND t1.price = t2.price

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