Converting MySQL results into comma separated values

Question

I have a mysql statement that will produce a bunch of results. I want to split each result with a comma except the last result. I was thinking that I would need a for loop but I am not quite sure how to go about it. Should I get my results as an array and loop through them? I was thinking that I should count the rows and then when the for reaches the last result it doesn't use a comma.

I am so used to just getting the results with while that I am a bit of a noob using for. I would appreciate any advice.

Obviously won't work because the last result will have a comma.

$sql = 'SELECT * FROM tags WHERE vid_id=?';
$stmt_tags = $conn->prepare($sql);
$result=$stmt_tags->execute(array($vid_id));
$tag_count=$stmt_tags->rowCount();
while ($row = $stmt_tags->fetch(PDO::FETCH_ASSOC)) {

    $tags=htmlspecialchars( $row['name'], ENT_NOQUOTES, 'UTF-8' );
    $tags=$tags.',';
    echo $tags;

}

Thanks in advance.

Answer 1

$tags = array();
while ($row = $stmt_tags->fetch(PDO::FETCH_ASSOC)) {
    $tags[] =htmlspecialchars( $row['name'], ENT_NOQUOTES, 'UTF-8' );
}
echo implode(',', $tags);

Answer 2

Put them all in a temporary array and use implode() .

implode(',',$array);

Answer 3

$alldata = $stmt_tags->fetchAll(PDO::FETCH_ASSOC);
$tags = implode(',' array_map(function($row){
    htmlspecialchars( $row['name'], ENT_NOQUOTES, 'UTF-8' );
},$alldata));

Answer 4

And without implode() —for completeness— just add the comma before ;it's easier to tell out the first row than the last one:

<?php

$tags = '';
$first = TRUE;
while ($row = $stmt_tags->fetch(PDO::FETCH_ASSOC)) {
    if($first){
        $first = FALSE;
    }else{
        $tags .= ', ';

    }
    $tags .= htmlspecialchars( $row['name'], ENT_NOQUOTES, 'UTF-8' );
}