creating archive for my blog website - php

Question

my database table is something like :
id year month
1 2011 november
2 2011 november
3 2011 october
i need to create a query so it return something like that :
2011
november
november
october
What is the correct query syntax to do it in php script ?
Here is the code i used :
<?php
$uid = $_SESSION['uid'];
$sql = "SELECT year, GROUP_CONCAT(month) AS months FROM articles GROUP BY year";
$res = mysql_query ($sql) or die (mysql_error());
if (mysql_num_rows($res) > 0) {
while ($rows = mysql_fetch_assoc($res)) {
foreach ($rows AS $row) {
echo $row['year'] . "<br>";
$months = explode(",", $row['months']);
foreach ($months AS $m) {
echo $m . "<br>";
}
}
}
}
?>

Answer 1

You can use GROUP_CONCAT() to return a comma-separated list of months:
SELECT year, GROUP_CONCAT(month) AS months GROM tbl GROUP BY year
Returns:
2011 november,november,october
Or just select both columns and handle the display/presentation in your code:
SELECT year, month FROM tbl WHERE year = 2011
Returns
2011 november
2011 november
2011 october
In code, loop and only display the year when it changes.
Update Since a code example seems warranted...
// Results from above GROUP_CONCAT() query already fetched & stored in `$rowset`:
while ($row = mysql_fetch_assoc($res)) {
$rowset[] = $row;
}
// Now $rowset is a 2D array containing all rows.
foreach ($rowset as $row) {
// Output the year
echo $row['year'] . "\n";
// months are comma-separated via GROUP_CONCAT()
// explode them into an array
$months = explode(",", $row['months']);
foreach ($months as $m) {
// Output the months
echo $m . "\n";
}
}

Answer 2

If I understood your question correctly, I think a simple "ORDER BY" clause would do the trick for you, something similar to:
SELECT * FROM table_name ORDER BY year DESC
Then, use your scripting language to display the data, a good idea could be (maybe) to fetch the year of the first row, store it in a temporal variable, then loop through the rows and check if the year has changed, if it has, change the value of the aforementioned variable, something like this:
$current_year = $data_set[0]['year'];
foreach ( $data_set as $data_row )
{
$current_year = ( $data_row['year'] != $current_year) ? $data_row['year'] : $current_year;
//Do something with it and/or the rest of the data
}
Hope this was of any help.
Cheers.