Fixes useless client helper complexity

src/Client.php

@@ -52,25 +52,16 @@ class Client
 
     public function getDatabases()
     {
-        if (!($this->getAdapter() instanceOf QueryableInterface)) {
-            throw new  \BadMethodCallException("You can query the database only if the adapter supports it!");
-        }
         return $this->getAdapter()->query("show databases");
     }
 
     public function createDatabase($name)
     {
-        if (!($this->getAdapter() instanceOf QueryableInterface)) {
-            throw new  \BadMethodCallException("You can query the database only if the adapter supports it!");
-        }
         return $this->getAdapter()->query("create database \"{$name}\"");
     }
 
     public function deleteDatabase($name)
     {
-        if (!($this->getAdapter() instanceOf QueryableInterface)) {
-            throw new  \BadMethodCallException("You can query the database only if the adapter supports it!");
-        }
         return $this->getAdapter()->query("drop database \"{$name}\"");
     }
 }

tests/unit/ClientTest.php

@@ -62,4 +62,22 @@ class ClientTest extends \PHPUnit_Framework_TestCase
             ]
         ]);
     }
+
+    /**
+     * @expectedException BadMethodCallException
+     */
+    public function testNeedWritableInterfaceDuringMark()
+    {
+        $client = new Client(new \stdClass());
+        $client->mark("OK", []);
+    }
+
+    /**
+     * @expectedException BadMethodCallException
+     */
+    public function testNeedQueryableInterfaceDuringQuery()
+    {
+        $client = new Client(new \stdClass());
+        $client->query("OK", []);
+    }
 }