I highly suggest using a one to many or many to many design for this rather than cramming the values into a single field. Doing this will cause issues in the future and maintenance will be a nightmare. If you provide a bit more information about what kind of data you're working with (What do the numbers represent? What uses the numbers?) I'd be happy to illustrate a more usable design.
That said, if you insist on having multiple values in a single field, you can use the PHP function explode():
$data_set = explode(',', $sql_data);
Updated Answer Based On Comment
In that case, there are a few ways you could do this. If the properties are always in the same order and represent the same thing (and there are only 5-6), I'd recommend just breaking them out into separate columns and naming the columns appropriately.
If there are a lot of potential properties and they're variable, I'd recommend creating a profiles table, a properties table (just id and name), and a profilesToProperties table. That will allow the most flexible adjustments to properties over time. To get all properties for a given profile, you'd do something like:
SELECT prof.username, prop.name
FROM profiles prof
LEFT JOIN profilesToProperties ptp ON prof.id = ptp.profile_id
LEFT JOIN properties prop ON prop.id = ptp.property_id
WHERE prop.id = :id
This would still return profiles with zero properties.
explode().$data_set = explode(',', $sql_data );:-) your question is not clear :-(