Get current user access level in Joomla 2.5 - php

Question

In Joomla 2.5.14, I have a script that gets the current user group id, like:
$groups = $user->get('groups');
foreach($groups as $group) {
echo "<p>Your group ID is:" . $group . "</p>";
};
Now, I need to count the number of articles this user is able to read, given his access level.
For that, I need to select the access level from the viewlevels table, that looks like this:
id title rules JSON encoded access control.
1 Public [1]
2 AccessA [13,8,16,17]
3 AccesssF [8]
4 AccessD [14,8]
6 AccessB [8,16,17]
7 AccessC [8,17]
So, for example, Group 17 may read the articles in AccessA, AccessB and Access C.
I tried the following query, but it isn't selecting any rows:
$query="SELECT * FROM xmb9d_viewlevels WHERE rules LIKE '%.$group.%'";
How can I select all the acess levels for the current user group and then count the number of articles he's able to read?
Thanks for helping!

Answer 1

First
https://github.com/joomla/joomla-cms/blob/master/libraries/joomla/access/access.php#L285
JAccess::getGroupsByUser($userId, $recursive = true)
Will get you the groups a user is matched to including via inheritance (unless you make $recursive false)
https://github.com/joomla/joomla-cms/blob/master/libraries/joomla/access/access.php#L402
JAccess::getAuthorisedViewLevels($userId) will give you all the view levels a user is allowed to see as an array.
If you do
$allowedViewLevels = JAccess::getAuthorisedViewLevels($userId);
if nothing else you could do
$implodedViewLevels = implode(',', $allowedViewLevels);
....
$query->select($db->quoteName('id'))
->from('#__content')
->where($db->quoteName('access') . 'IN (' . $implodedViewLevels . ')';
....
(not tested but you get the general idea).
In joomla always try to let the api do the work for you rather than fight with it.

Answer 2

I think you just need to remove the periods from within the LIKE clause. Such as:
$query="SELECT * FROM xmb9d_viewlevels WHERE rules LIKE '%$group%'";
Also, to make it not specific to the database you should substitute #__ (Note: it's two underscores) for the table prefix:
$query="SELECT * FROM #__viewlevels WHERE rules LIKE '%$group%'";