PHP JSON array from query - php

Question

I'm not a php developer, but trying to get an array within an array from this query:
SELECT distinct d.DiscussionId as DiscussionId, d.AvatarId as AvatarId, d.Heading as Heading, d.body as Body, c.commentid as CommentId, c.userid as UserId, c.comment as Comment
FROM Discussion AS d
INNER JOIN Comments AS c ON d.discussionid = c.discussionid
WHERE d.DiscussionId = c.DiscussionId
The JSON output is:
[
{
"DiscussionId": "1",
"AvatarId": null,
"Heading": "New discussion heading",
"Body": "This is the discussion body",
"Comments": [
{
"DiscussionId": "1",
"CommentId": "1",
"UserId": "2",
"Comment": "This is a comment i made"
}
]
},
{
"DiscussionId": "1",
"AvatarId": null,
"Heading": "New discussion heading",
"Body": "This is the discussion body",
"Comments": [
{
"DiscussionId": "1",
"CommentId": "2",
"UserId": "2",
"Comment": "This is a second comment"
}
]
}
]
What I need is to nest all Comments in one Discussion.
the php code is below, no error but not giving the output i want, for each discussion there maybe several comments so i need DiscussionId:1 displayed only once with multilple comments array
$result = mysql_query($query,$link) or die('Errant query: '.$query);
$model = array();
$record = -1;
$currentWeID = -1;
while($e = mysql_fetch_assoc($result)){
$record++;
$model[] = array();
$model[$record]['DiscussionId'] = $e['DiscussionId'];
$model[$record]['AvatarId'] = $e['AvatarId'];
$model[$record]['Heading'] = $e['Heading'];
$model[$record]['Body'] = $e['Body'];
$model[$record]['Comments'][] = array(
'DiscussionId'=> $e['DiscussionId'],
'CommentId' => $e['CommentId'],
'UserId' => $e['UserId'],
'Comment' => $e['Comment']
);
}
print json_encode ($model);

Answer 1

You are selecting many comments from a single dicussion.
You should overwrite that variable instead of creating a new element at each iteration:
$model = array();
while($e = mysql_fetch_assoc($result)){
//We overwrite the same variable, that's ok
$model['DiscussionId'] = $e['DiscussionId'];
$model['AvatarId'] = $e['AvatarId'];
$model['Heading'] = $e['Heading'];
$model['Body'] = $e['Body'];
//Only comments would be an array
$model['Comments'][] = array(
'DiscussionId'=> $e['DiscussionId'],
'CommentId' => $e['CommentId'],
'UserId' => $e['UserId'],
'Comment' => $e['Comment']
);
}

Answer 2

try it like this:
Added Disscussion Id as an index for the array, should work for you. Just off the top of my head, not tested.
$result = mysql_query($query,$link) or die('Errant query: '.$query);
$model = array();
$record = -1;
$currentWeID = -1;
$model = array();
while($e = mysql_fetch_assoc($result)){
$record++;
$model[$e['DiscussionId']][$record]['AvatarId'] = $e['AvatarId'];
$model[$e['DiscussionId']][$record]['Heading'] = $e['Heading'];
$model[$e['DiscussionId']][$record]['Body'] = $e['Body'];
$model[$e['DiscussionId']][$record]['Comments'][] = array(
'DiscussionId'=> $e['DiscussionId'],
'CommentId' => $e['CommentId'],
'UserId' => $e['UserId'],
'Comment' => $e['Comment']
);
}
print json_encode ($model);

Answer 3

Try this:
$result = mysql_query($query,$link) or die('Errant query: '.$query);
$model = array();
$record = 0;
$currentWeID = -1;
while($e = mysql_fetch_assoc($result)){
$model[] = array();
$model[$record][$e['DiscussionId']]['AvatarId'] = $e['AvatarId'];
$model[$record][$e['DiscussionId']]['Heading'] = $e['Heading'];
$model[$record][$e['DiscussionId']]['Body'] = $e['Body'];
$model[$record][$e['DiscussionId']]['Comments'][] = array(
'DiscussionId'=> $e['DiscussionId'],
'CommentId' => $e['CommentId'],
'UserId' => $e['UserId'],
'Comment' => $e['Comment']
); ;
$record++;
}
print json_encode ($model);
This might help you. Dont forget to accept answer if it helps.

Answer 4

It's not possible with just changing the SQL query: you need to change the server-side code (PHP, as I understand) which transorms query results to JSON.