显示的查询结果之间的间距

Question

I am new to php and MySQL.

I am making a script on my website, that deals with mobile downloads.

I have 3 tables set up that I am dealing with here.

1. downloads (contains info about a specific download, each with its own id).
2. models (contains a list a possible device models(model names), each with its own id).
3. downloads_models (linking table stating download_id = model_id, eg. (1,2) (1,3) (2,1)).

I have a simple query to display the models that support each specific download. It goes as follows:

    $dlDetailsQuery = 'SELECT models.model
    FROM models,downloads_models
    WHERE downloads_models.modId = models.model_id
    AND downloads_models.downId = "'.$pageId.'"
    ORDER BY models.model ASC; 
    ';

To display which models support the download, this line is echod:

    $dpModSupport .= stripslashes($row['model']);

Now as an example, my page has a $pageId of "1" which is the download "example1", "example1" supports models 1(model1), 2(model2) and 3(model3). When$dpModSupport is echod, it echoes as "model1model2model3".

My question is this: how do I get spacing, or a comma between the results?

What I am aiming for is an output of "model1, model2, model3".

I'm looking for a way to do this via php. I don't know whether a query can be structured to output spacing between results, so I'm guessing that php is the only solution there.

I do not want to add the spacing or commas into the model name field, or create a new field containing the spacing or commas along with the model's name.

Answer 1

Problem

By writing this in a loop:

$dpModSupport .= stripslashes($row['model']);

you're building up a string like this:

$dpModSupport .= stripslashes(<MODEL1>);
$dpModSupport .= stripslashes(<MODEL2>);
$dpModSupport .= stripslashes(<MODEL3>);

thus ending up with a string that's just the contents of each row splattered next to each other.

---

Solution

Instead, you could write this before your loop:

$dpModSupport = Array();

And then, inside it, instead of the line with .= building up a string, build up the array:

$dpModSupport[] = stripslashes($row['model']);

Finally, to obtain output consisting of each element of said array, joined by a comma:

echo implode(', ', $dpModSupport);

I will leave it as an exercise to the reader to look up these functions and language features in the PHP manual.