Remove support for outdated DBAL.

README.md

@@ -6,11 +6,9 @@ About NADA
 
 NADA is a high level SQL abstraction library for PHP. It complements and
 operates on top of a conventional database abstraction layer (currently
-supported: [PDO](http://php.net/manual/en/book.pdo.php),
-[Zend_Db (Zend Framework 1.x)](http://framework.zend.com),
-[Zend\Db (Zend Framework 2.x)](http://framework.zend.com) and
-[MDB2](http://pear.php.net/package/MDB2)), allowing easy integration into
-existing applications.
+supported: [PDO](http://php.net/manual/en/book.pdo.php) and
+[Laminas-DB](https://docs.laminas.dev/laminas-db/)), allowing easy integration
+into existing applications.
 
 NADA provides SQL abstraction methods for different database backends (currently
 supported: [PostgreSQL](http://postgresql.org), [MySQL](http://mysql.org) and

src/Factory.php

@@ -59,12 +59,6 @@ static function getDatabase($link)
             $class = 'Pdo';
         } elseif ($link instanceof \Laminas\Db\Adapter\Adapter) {
             $class = 'LaminasDb';
-        } elseif ($link instanceof \Zend\Db\Adapter\Adapter) {
-            $class = 'ZendDb2';
-        } elseif ($link instanceof \Zend_Db_Adapter_Abstract) {
-            $class = 'ZendDb';
-        } elseif ($link instanceof \MDB2_Driver_Common) {
-            $class = 'Mdb2';
         } else {
             throw new \InvalidArgumentException('Unsupported link type');
         }