如何获取每个类别的最新帖子

Question

I create a website with PHP and MySQL, I have a table with the following rows ID - POST TITLE - CATEGORY. right now I have 10 posts published on three different categories (sport, health, world) and I want a sql allows me to get the latest post from each category.

I tried this

<?php 
    $scat_sql = mysql_query("select * from videos where category = 'sport' order by id desc limit 1"); 
    while($scat_row = mysql_fetch_assoc($scat_sql)){
        $scat_link = $scat_row['post title'];
    }
?>

but the problem is I need to repeat this code for each category. The output that I want looks like this :

Health

The latest post of health category

Sport

The latest post of sport category

world

The latest post of world category

Answer 1

I would add a datetime field to the table if you don't already have that, something like date_posted . When you add a new post, insert the current date and time into date_posted along with the other fields.

When you want the three latest posts in each category, you can use a group by statement along with the min function on date_posted .

select * from videos
inner join (
    select min(date_posted) date_posted from videos group by category
) recent on (recent.date_posted = videos.date_posted);

The select in the inner join gets the most recent date_posted for each category. The inner join matches and joins that date_posted with the correct row to get the other values.

Answer 2

$command = "SELECT * FROM videos WHERE category='sport' ORDER BY id DESC LIMIT 1";
$result = mysql_query ($command) or die ("<strong>Error:</strong> ". mysql_error());
while ($row = mysql_fetch_array ($result))
    {
       echo $row[name_of_the_column_you_want_to_echo]; 
    };

That should do it.

Answer 3

If you simply want to shorten your code you could insert your categories (tables) into a array or a another table. Read out that table or array in a loop and make the table in your query a variable.