How to display all comments per article (PHP & SQL)? - php

Question

So I have two tables, article and comments (which has one-to-many relationship (1 article - many comments)). This is how the table is structured:
Articles - id (prikey), title, publicationDate, content
Comments - com_id (prikey), author, comment, id (foreign key)
I used this to query the two tables:
SELECT * FROM articles as a INNER JOIN comments as c ON a.id = c.id
Previously, I was only displaying the articles table using this:
<?php
while($row = mysqli_fetch_array($query)) {
echo "
<div id='article'>
<header>
<hgroup>
<h2>".$row['title']."</h2>
<h4>Posted on ".$row['publicationDate']."</h4>
</hgroup>
</header><p>".$row['content']."</p></div>";
}
?>
This displays all articles (with date, title, content, etc.). Now there are comments. How do I edit the php code (or if my query is incorrect, how to write the query), so that it shows all articles and all comments per article as in:
Article One
-- Comment 1
-- Comment 2, etc.
Article Two
-- Comment 1
-- Comment 2, etc.

Answer 1

An alternative would be to split the query into two.
The first would bring back the articles you want...
SELECT * FROM article;
Once you have those, you can get all the IDs and use something like the following
SELECT * FROM comments WHERE article_id IN (".$list.");
This restricts the MySQL queries to 2 whilst getting all the data you need. After this loop around the article data, and in that loop, loop around the comments data.
This also means that, unlike using GROUP_CONCAT, you will also have author data to use.
It's not a very eloquent solution, but should work.

Answer 2

Query:
SELECT c.author, c.comment,
a.id article_id, a.title, a.publicationDate, a.content
FROM comments c
RIGHT JOIN articles a
ON c.id = a.id
PHP:
<?php
$lastArticleId = 0;
$isNewArticle = false;
while($row = mysqli_fetch_array($query)) {
$isNewArticle = ($lastArticleId != $row['article_id']) ? true : false;
if($isNewArticle) {
$lastArticleId = $row['article_id']; ?>
<div class="article">
<header>
<hgroup>
<h2><?php echo $row['title']; ?></h2>
<h4>Posted on <?php echo $row['publicationDate']; ?></h4>
</hgroup>
</header>
<p><?php echo $row['content']; ?></p>
</div>
<?php
}
if($row['comment'] != '') { ?>
<p><strong><?php echo $row['author']; ?></strong> - <?php echo $row['comment']; ?></p>
<?php
} ?>
<?php
} ?>

Answer 3

Use something like
SELECT a.article
,GROUP_CONCAT(CONCAT('<p>', c.comment, '</p>') SEPARATOR "\n") as comments
FROM
article a
INNER JOIN comment c ON (c.article_id = a.id)
WHERE a.id = '12454';
You may have to fiddle a bit with the separator.
See: http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat
Do note however:
The result is truncated to the maximum length that is given by the group_concat_max_len system variable, which has a default value of 1024. The value can be set higher, although the effective maximum length of the return value is constrained by the value of max_allowed_packet. The syntax to change the value of group_concat_max_len at runtime is as follows, where val is an unsigned integer:
SET [GLOBAL | SESSION] group_concat_max_len = val;
See here how to change max_allowed_packet
http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html#sysvar_max_allowed_packet

Answer 4

Look into MySQL GROUP_CONCAT which will return a comma delimited list of items. You can then explode that for your comments section.

Answer 5

once a person will comment on a article insert article id with that comment and later get them accordingly something like this
once a person will select an article to read send article id in the $_GET to your article page so you can excess the article id.Once a person will comment on that article insert it as follows
$sql = mysql_query("INSERT INTO comments_table (subject,article_id,comments) VALUES ('$subject','$_GET['id']','$comments')");
and later when you pulling them do it the same way as you have the article id in the $_GET
you can access it run a query like this
$fetch = mysql_query("SELECT * FROM comments WHERE article_id = $_GET['id'] ORDER BY id DESC") or die(mysql_error());
Hope this will work