As of PHP 5.4 support for Sqlite2 has been removed. I have a large web app that was built with sqlite2 as the database backend and thus it exploded when I updated PHP. If you're in a similar situation I've written a few wrapper functions that will allow your app to work whilst you convert the code to sqlite3.
Firstly convert your DB to an sqlite3 db.
sqlite OLD.DB .dump | sqlite3 NEW.DB
Then add the following functions to your app:
$handle = new SQLite3($location);
$array['dbhandle'] = $dbhandle;
$array['query'] = $query;
$result = $dbhandle->query($query);
$i = 0;
$columns[ ] = $result->columnName($i);
$resx = $result->fetchArray(SQLITE3_ASSOC);
They're not perfect by any stretch but they seem to be working ok as a temporary measure while I convert the site.
Hope that helps someone