Joomla 2.5中的查询数据库

Question

I'm using Joomla 2.5 and I need to retrieve the field 'avatar' for the current user.

This is the code I'm using:

$user = JFactory::getUser();
$id = $user->get('id');

$db = JFactory::getDbo();
$query = $db->getQuery(true);

$query->select('avatar')
 ->from('#__discuss_users')
 ->where('id = $id');

$db->setQuery($query);
$results = $db->loadObjectList();

But it isn't displaying any data. I tried changing the last line to:

$results = $db->loadResult();

But it doesn't work either.

Answer 1

If you are using it as you posted, you won't include the actual value of $id in your query. You need to append it to the string like this:

$query->select('avatar')
 ->from('#__discuss_users')
 ->where('id = '.$id);

I am usually not using the $query->select stuff, but a plain old query. Thus, you might try to do it like this (this might not be best practice though):

$user = JFactory::getUser();
$id = $user->get('id');

$db = JFactory::getDBO();  
// $query = $db->getQuery(true);

$query = "SELECT ".$db->quoteName('avatar')
         ." FROM ".$db->quoteName('#__discuss_users')
         ." WHERE ".$db->quoteName('id')
         ." = ".$db->quote($id).";";

// $query->select('avatar')
// ->from('#__discuss_users')
// ->where('id = $id');

$db->setQuery($query);
$results = $db->loadObjectList();

Answer 2

Thanks for your help. The following code works:

$user = JFactory::getUser();
$id = $user->get('id');

$db = JFactory::getDbo();
$query = $db->getQuery(true);

$query
 ->select($db->quoteName('avatar'))
 ->from($db->quoteName('#__discuss_users'))
 ->where('id = '.$id);

$db->setQuery($query);
$results = $db->loadResult();
echo $results;