added facade composite and adapter

Adapter/Adapter.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace DesignPatterns;
+
+/**
+ * adapter pattern
+ *
+ * Purpose:
+ * to link two systems, that have different interfaces. An adapter defines interfaces that are equal for all linked
+ * systems and wrap functionality
+ *
+ * Examples:
+ * - different databases have the same interface to communicate although the underlying systems act differently
+ * 
+ * this is a VERY basic example which won't work at all
+ */
+interface DatabaseAdapter
+{
+    public function getTables();
+}
+
+class MySQL implements DatabaseAdapter
+{
+    public function getTables()
+    {
+        return $this->select('SHOW TABLES');
+    }
+}
+
+class SQLite implements DatabaseAdapter
+{
+    public function getTables()
+    {
+        return system('sqlite --list-tables');
+    }
+}
+