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Mysql: Extract categories and the latest article in each category.

Posted on 2008-10-02
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Last Modified: 2012-05-05
Hi,

I have 2 tables:
- news: contains all the articles
- cat news: contains the categories of the articles.

I would like to extract all the the categories and the latest article in each category.
Basically, what I want is to extract all the latest articles grouped by its relative category.  (each article is asigned to only 1 category).

This is the set of data I want to extract:
id_cat_news      |      cat_news_nome      |      id_news      |      news_titolo      |      news_data_mod

This is the query I'm using:
SELECT cat_news.id_cat_news,cat_news.cat_news_nome,news.id_news,news.news_titolo,news.news_data_mod
FROM news
LEFT JOIN cat_news on news.id_cat_news=cat_news.id_cat_news
GROUP BY cat_news.id_cat_news
ORDER BY news.news_data_mod desc

It extracts all the data I want but it doesn't extract the latest article in each category.

How can I modify this query in order to extract also the latest articles in each category.

Please let me know.
-L.
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Question by:Laurent Belin
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2 Comments
 
LVL 25

Accepted Solution

by:
Tomas Helgi Johannsson earned 2000 total points
ID: 22622703
     Hi

This would work

Regards,
   Tomas Helgi

SELECT c.id_cat_news,c.cat_news_nome,n.id_news,n.news_titolo,n.news_data_mod
FROM news n, cat_news c
WHERE n.id_cat_news=c.id_cat_news
AND n.id_news = (select max(nn.id_news) from news nn where nn.id_cat_news = n.id_cat_news)
GROUP BY c.id_cat_news
ORDER BY n.news_data_mod desc

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Author Closing Comment

by:Laurent Belin
ID: 31502309
Thank you!
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