diff --git a/DataStorage/Database/Connection/MysqlConnection.php b/DataStorage/Database/Connection/MysqlConnection.php
index af4c2ed02..719031e69 100644
--- a/DataStorage/Database/Connection/MysqlConnection.php
+++ b/DataStorage/Database/Connection/MysqlConnection.php
@@ -20,6 +20,7 @@ use phpOMS\DataStorage\Database\DatabaseStatus;
 use phpOMS\DataStorage\Database\DatabaseType;
 use phpOMS\DataStorage\Database\Query\Grammar\MysqlGrammar;
 use phpOMS\DataStorage\Database\Schema\Grammar\MysqlGrammar as MysqlSchemaGrammar;
+use phpOMS\DataStorage\Database\Exception\InvalidConnectionConfigException;
 
 /**
  * Database handler.
@@ -62,27 +63,27 @@ class MysqlConnection extends ConnectionAbstract
         $this->dbdata = isset($dbdata) ? $dbdata : $this->dbdata;
         
         if(!isset($this->dbdata['db'])) {
-            throw new \Exception('db');
+            throw new InvalidConnectionConfigException('db');
         }
 
         if(!isset($this->dbdata['host'])) {
-            throw new \Exception('host');
+            throw new InvalidConnectionConfigException('host');
         }
 
         if(!isset($this->dbdata['port'])) {
-            throw new \Exception('port');
+            throw new InvalidConnectionConfigException('port');
         }
 
         if(!isset($this->dbdata['database'])) {
-            throw new \Exception('database');
+            throw new InvalidConnectionConfigException('database');
         }
 
         if(!isset($this->dbdata['login'])) {
-            throw new \Exception('login');
+            throw new InvalidConnectionConfigException('login');
         }
 
         if(!isset($this->dbdata['password'])) {
-            throw new \Exception('password');
+            throw new InvalidConnectionConfigException('password');
         }
 
         $this->close();
diff --git a/DataStorage/Database/DataMapperAbstract.php b/DataStorage/Database/DataMapperAbstract.php
index 7552b6324..7165af099 100644
--- a/DataStorage/Database/DataMapperAbstract.php
+++ b/DataStorage/Database/DataMapperAbstract.php
@@ -20,6 +20,7 @@ use phpOMS\DataStorage\Database\Connection\ConnectionAbstract;
 use phpOMS\DataStorage\Database\Query\Builder;
 use phpOMS\DataStorage\DataMapperInterface;
 use phpOMS\Message\RequestAbstract;
+use phpOMS\DataStorage\Database\Exception\InvalidMapperException;
 
 /**
  * Datamapper for databases.
@@ -460,7 +461,7 @@ class DataMapperAbstract implements DataMapperInterface
      *
      * @return void
      *
-     * @throws \Exception
+     * @throws InvalidMapperException
      *
      * @since  1.0.0
      */
@@ -480,7 +481,7 @@ class DataMapperAbstract implements DataMapperInterface
             }
 
             if (!isset(static::$hasMany[$propertyName]['mapper'])) {
-                throw new \Exception('No mapper set for relation object.');
+                throw new InvalidMapperException();
             }
 
             /** @var DataMapperAbstract $mapper */
@@ -679,7 +680,7 @@ class DataMapperAbstract implements DataMapperInterface
      *
      * @return void
      *
-     * @throws \Exception
+     * @throws InvalidMapperException
      *
      * @since  1.0.0
      */
@@ -699,7 +700,7 @@ class DataMapperAbstract implements DataMapperInterface
             }
 
             if (!isset(static::$hasMany[$propertyName]['mapper'])) {
-                throw new \Exception('No mapper set for relation object.');
+                throw new InvalidMapperException();
             }
 
             /** @var DataMapperAbstract $mapper */
@@ -984,7 +985,7 @@ class DataMapperAbstract implements DataMapperInterface
      *
      * @return void
      *
-     * @throws \Exception
+     * @throws InvalidMapperException
      *
      * @since  1.0.0
      */
@@ -1004,7 +1005,7 @@ class DataMapperAbstract implements DataMapperInterface
             }
 
             if (!isset(static::$hasMany[$propertyName]['mapper'])) {
-                throw new \Exception('No mapper set for relation object.');
+                throw new InvalidMapperException();
             }
 
             /** @var DataMapperAbstract $mapper */
@@ -1406,7 +1407,7 @@ class DataMapperAbstract implements DataMapperInterface
      *
      * @return mixed
      *
-     * @throws \Exception
+     * @throws \UnexpectedValueException
      *
      * @since  1.0.0
      */
diff --git a/DataStorage/Database/Exception/InvalidConnectionConfigException.php b/DataStorage/Database/Exception/InvalidConnectionConfigException.php
new file mode 100644
index 000000000..f3fec1deb
--- /dev/null
+++ b/DataStorage/Database/Exception/InvalidConnectionConfigException.php
@@ -0,0 +1,44 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.1
+ *
+ * @category   TBD
+ * @package    TBD
+ * @author     OMS Development Team <dev@oms.com>
+ * @copyright  Dennis Eichhorn
+ * @license    OMS License 1.0
+ * @version    1.0.0
+ * @link       http://orange-management.com
+ */
+declare(strict_types=1);
+
+namespace phpOMS\DataStorage\Database\Exception;
+
+/**
+ * Permission exception class.
+ *
+ * @category   Framework
+ * @package    phpOMS\System\File
+ * @author     OMS Development Team <dev@oms.com>
+ * @license    OMS License 1.0
+ * @link       http://orange-management.com
+ * @since      1.0.0
+ */
+class InvalidConnectionConfigException extends \RuntimeException
+{
+    /**
+     * Constructor.
+     *
+     * @param string     $message Exception message
+     * @param int        $code    Exception code
+     * @param \Exception Previous exception
+     *
+     * @since  1.0.0
+     */
+    public function __construct(string $message = '', int $code = 0, \Exception $previous = null)
+    {
+        parent::__construct('Missing config value for "'. $message .'".', $code, $previous);
+    }
+}
diff --git a/DataStorage/Database/Exception/InvalidMapperException.php b/DataStorage/Database/Exception/InvalidMapperException.php
new file mode 100644
index 000000000..4e914f79d
--- /dev/null
+++ b/DataStorage/Database/Exception/InvalidMapperException.php
@@ -0,0 +1,48 @@
+<?php
+/**
+ * Orange Management
+ *
+ * PHP Version 7.1
+ *
+ * @category   TBD
+ * @package    TBD
+ * @author     OMS Development Team <dev@oms.com>
+ * @copyright  Dennis Eichhorn
+ * @license    OMS License 1.0
+ * @version    1.0.0
+ * @link       http://orange-management.com
+ */
+declare(strict_types=1);
+
+namespace phpOMS\DataStorage\Database\Exception;
+
+/**
+ * Permission exception class.
+ *
+ * @category   Framework
+ * @package    phpOMS\System\File
+ * @author     OMS Development Team <dev@oms.com>
+ * @license    OMS License 1.0
+ * @link       http://orange-management.com
+ * @since      1.0.0
+ */
+class InvalidMapperException extends \RuntimeException
+{
+    /**
+     * Constructor.
+     *
+     * @param string     $message Exception message
+     * @param int        $code    Exception code
+     * @param \Exception Previous exception
+     *
+     * @since  1.0.0
+     */
+    public function __construct(string $message = '', int $code = 0, \Exception $previous = null)
+    {
+        if($message === '') {
+            parent::__construct('Empty mapper.', $code, $previous);
+        } else {
+            parent::__construct('Mapper "' . $message . '" is invalid.', $code, $previous);
+        }
+    }
+}