Sql and php to group data by posted year, day and month

Question

I have been trying to show post from data base according to posted year and month but was unable to do this as i have tried everything i can, but still think this can be done in SQL QUERY and support it in PHP side. Below is my databse structure

id  | title                |  date 
-------------------------------------------------
1   | hello this is a post | 2016-01-03 11:33 AM
2   | this is what i think | 2016-01-03 10:33 PM
3   | this is it           | 2017-14-06 06:33 PM
4   | Blah Blah Blah       | 2017-01-03 10:33 AM
5   | is what i think      | 2016-04-03 10:33 PM

Now i want to select and group it this way

Your post on 2016-01-03

hello this is a post

this is what i think Your

post on 2017-14-06

this is it

Your post on 2017-01-03

Blah Blah Blah

Your post on 2017-01-03

is what i think

I tried doing this with bellow code

<?php
//I swear i don't know what else to do here
$db->prepare('SELECT * FROM post 
GROUP BY ("")
ORDER BY date');
$db->execute();
$output = $db->getAll();
$db->free();
if(!is_null($output)){
foreach($output as $row){
$title = $row->title;
$date = $row->date;

/* 
 Only this path i got near but i can only display post for this month using   $currentDate below.
But how can i get other once split according to date?
*/

$split = explode(" ", $date);
$currentDate = date('Y-m-d');
if($split[0] == $currentDate){
  echo 'post on '.$currentDate.'<br/>'.$title;
}else{
   echo 'post on '.$split[0].'<br/>'.$title;
 }
?>

Answer 1

You have three requirements here. One is to render the date of a post without the time. The second is to order the posts by date/time.

Those can be done with a query like this.

SELECT DATE(`date`) as date, `title` FROM post ORDER BY `date`

GROUP BY serves no purpose for this.

The third requirement is to render the date only once when it's the same for consecutive posts. This must be done in php.

$prev_date = "";
foreach ($output as $row) {
    $title = $row->title;
    $date = $row->date;
    if ($date != $prev_date) {
        echo "Posts on " .$date;
    }
    echo information about the post
    $prev_date = $date;
}

The trick is to use the variable I've named $prev_date to detect when the date changes from row to row.

Answer 2

My favorite method is always put result into array first.

$date = date('Y-m-d', strtotime($row['date']));
$result[$date][] = $row['title'];

From the array above you can output the result using foreach .

foreach($result as $key => $value) {
    echo 'Your post on '.$key.'<br>';
    foreach($value as $k => $v) {
        echo $v.'<br>';
    }
}