diff --git a/src/admin/common/abstract/model.php b/src/admin/common/abstract/model.php
index c24aa46..2a7dce1 100644
--- a/src/admin/common/abstract/model.php
+++ b/src/admin/common/abstract/model.php
@@ -6,12 +6,9 @@ use Joomla\CMS\Factory;
 // No direct access.
 defined('_JEXEC') or die;
 
-class AssociatedObjectUnsavedException extends Exception
-{}
-
 abstract class AbstractCommonClubsModel
 {
-    // TODO Adddata validator
+    // TODO Add data validator
     // TODO Make setting of values attribute fail in case of problems
     // FIXME Add Joins in select statements
     
@@ -103,10 +100,9 @@ abstract class AbstractCommonClubsModel
         $db = Factory::getDbo();
         $q = $db->getQuery(true);
         
-        foreach($attribs as $k => $v)
+        foreach($attribs as $a)
         {
-            $rawColName = isset($v['col']) ? $v['col'] : $k;
-            $q->select($q->qn($rawColName, $k));
+            $a->select($q);
         }
         $q->from($factory->getTableName());
         $q->where("id = {$this->id}");
@@ -123,22 +119,10 @@ abstract class AbstractCommonClubsModel
     
     private function packExternalReferencesAsKeys($vals)
     {
-        foreach($this->getFactory()->getAttributes() as $k => $v)
+        foreach($this->getFactory()->getAttributes() as $a)
         {
-            if($v['type'] !== 'ref')
-                continue;
-            
-            if(is_null($vals[$k]))
-                continue;
-            
-            $id = $vals[$k]->getId();
-            
-            if($id === 'new')
-            {
-                throw new AssociatedObjectUnsavedException();
-            }
-            
-            $vals[$k] = $id;
+            $alias = $a->getAlias();
+            $vals[$alias] = $a->packValue($vals[$alias]);
         }
         
         return $vals;
@@ -146,64 +130,20 @@ abstract class AbstractCommonClubsModel
     
     private function unpackExternalReferencesFromKeys($vals)
     {
-        foreach($this->getFactory()->getAttributes() as $k => $v)
+        foreach($this->getFactory()->getAttributes() as $a)
         {
-            if(empty($v['type']) || $v['type'] !== 'ref')
-                continue;
-            
-            if(empty($v['ref']))
-                throw new Exception('External reference of unknown class found.');
-            
-            if(empty($vals[$k]))
-                continue;
-            
-            $vals[$k] = $this->loadExternalReferenceAsObject($v['ref'], $vals[$k]);
+            $alias = $a->getAlias();
+            $vals[$alias] = $a->unpackValue($vals[$alias]);
         }
         
         return $vals;
     }
     
-    private function loadExternalReferenceAsObject($className, $value)
-    {
-        if(is_string($value) && preg_match('/^[0-9]+$/', $value))
-            $value = (int) $value;
-        
-        if(! is_int($value))
-            throw new Exception('Reference with non-integer value');
-        
-        $factoryName = $this->getFactoryNameOfClass($className);
-        $factory = new $factoryName();
-        return $factory->loadById($value);
-    }
-    
-    private const CLASSNAME_MAP = array(
-        
-    );
-    
-    /**
-     * @todo This must be done better and more cleanly
-     * @param string $className
-     * @return AbstractCommonClubsModelFactory
-     */
-    private function getFactoryNameOfClass($className)
-    {
-        if(empty(self::CLASSNAME_MAP[$className]))
-        {
-            $parts = array();
-            if(preg_match('/^CommonClubsModel(.*)/', $className, $parts))
-            {
-                return "CommonClubsModelFactory{$parts[1]}";
-            }
-            throw new Exception("Unknown mapping of class $className");
-        }
-        
-        return self::CLASSNAME_MAP[$className];
-    }
     
     /**
      * 
      * @param array $rawData
-     * @param array $attribs
+     * @param AbstractCommonClubsModelColumn[] $attribs
      * @param JDatabaseQuery $q
      * @return string[]|number[]|NULL[]
      */
@@ -211,38 +151,10 @@ abstract class AbstractCommonClubsModel
     {
         $quotedData = array();
         
-        foreach($attribs as $k => $v)
+        foreach($attribs as $a)
         {
-            if(empty($v['type']))
-                $v['type'] = 'string';
-            
-            if($rawData[$k] === NULL)
-            {
-                $quotedData[$k] = 'NULL';
-                continue;
-            }
-            
-            switch($v['type'])
-            {
-                case 'string':
-                    $quotedData[$k]  = $q->q($rawData[$k]);
-                    break;
-                    
-                case 'int':
-                    $quotedData[$k] = (int) $rawData[$k];
-                    break;
-                    
-                case 'float':
-                    $quotedData[$k] = (float) $rawData[$k];
-                    break;
-                    
-                case 'ref':
-                    if($v['ref'] === null)
-                        $quotedData[$k] = 'NULL';
-                    else
-                        $quotedData[$k] = $rawData[$k]->getId();
-                    break;
-            }
+            $alias = $a->getAlias();
+            $quotedData[$alias] = $a->getQuotedValue($q, $rawData[$alias]);
         }
         
         return $quotedData;
@@ -277,7 +189,7 @@ abstract class AbstractCommonClubsModel
     
     /**
      * 
-     * @param array $attribs
+     * @param AbstractCommonClubsModelColumn[] $attribs
      * @param AbstractCommonClubsModelFactory $factory
      * @param JDatabaseQuery $q
      */
@@ -286,9 +198,9 @@ abstract class AbstractCommonClubsModel
         $q->insert($factory->getTableName());
         
         $dbcols = array();
-        foreach($attribs as $k => $v)
+        foreach($attribs as $a)
         {
-            $dbcols[] = isset($v['col']) ? $v['col'] : $k;
+            $dbcols[] = $a->getColumn();
         }
         
         $q->columns($q->qn($dbcols));
@@ -310,7 +222,7 @@ abstract class AbstractCommonClubsModel
     
     /**
      * 
-     * @param array $attribs
+     * @param AbstractCommonClubsModelColumn[] $attribs
      * @param AbstractCommonClubsModelFactory $factory
      * @param JDatabaseQuery $q
      */
@@ -319,8 +231,8 @@ abstract class AbstractCommonClubsModel
         $q->update($factory->getTableName());
         
         $dbcols = array();
-        foreach($attribs as $k => $v)
-            $dbcols[] = isset($v['col']) ? $v['col'] : $k;
+        foreach($attribs as $a)
+            $dbcols[] = $a->getColumn();
         
         $quotedData = $this->getQuotedData($attribs, $q);
         
diff --git a/src/admin/common/abstract/model/column.php b/src/admin/common/abstract/model/column.php
new file mode 100644
index 0000000..a21ceee
--- /dev/null
+++ b/src/admin/common/abstract/model/column.php
@@ -0,0 +1,74 @@
+<?php
+
+// No direct access.
+defined('_JEXEC') or die;
+
+abstract class AbstractCommonClubsModelColumn
+{
+    
+    protected $alias;
+    protected $column;
+    protected $required;
+    
+    public function getAlias()
+    {
+        return $this->alias;
+    }
+    
+    public function getColumn()
+    {
+        return $this->column;
+    }
+    
+    public function isRequired()
+    {
+        return $this->required;
+    }
+    
+    public abstract function isSimpleType();
+    
+    public function __construct($alias, $required = true, $column = null)
+    {
+        $this->alias = $alias;
+        $this->required = $required;
+        if(isset($column))
+            $this->column = $column;
+        else
+            $this->column = $alias;
+    }
+    
+    /**
+     * @param JDatabaseQuery $q
+     */
+    public function select($q)
+    {
+        $q->select($q->qn($this->column, $this->alias));
+    }
+    
+    /**
+     * 
+     * @param JDatabaseQuery $q
+     * @param mixed $value
+     */
+    public abstract function getQuotedValue($q,$value);
+    
+    /**
+     * 
+     * @param JDatabaseQuery $q
+     */
+    public function getQuotedColumnName($q)
+    {
+        return $q->qn($this->column);
+    }
+    
+    public function packValue($value)
+    {
+        return $value;
+    }
+    
+    public function unpackValue($value)
+    {
+        return $value;
+    }
+    
+}
diff --git a/src/admin/common/abstract/model/factory.php b/src/admin/common/abstract/model/factory.php
index a0f2aac..391ad64 100644
--- a/src/admin/common/abstract/model/factory.php
+++ b/src/admin/common/abstract/model/factory.php
@@ -36,6 +36,10 @@ abstract class AbstractCommonClubsModelFactory
     protected abstract function fetchAttributes();
     
     private $attributes = null;
+    /**
+     * @param boolean $force
+     * @return AbstractCommonClubsModelColumn[]
+     */
     public function getAttributes($force = False)
     {
         if($this->attributes === null || $force)
@@ -164,10 +168,15 @@ abstract class AbstractCommonClubsModelFactory
         $obj = $this->generatePlainObject('new');
         $obj->markAsNew(true);
         
-        $attribs = array_map(function($v){
-            return Null;
-        }, $this->getAttributes());
-        $obj->setValues($attribs);
+        $values = array();
+        foreach($this->getAttributes() as $a)
+        {
+            $values[$a->getAlias()] = null;
+        }
+//         $attribs = array_map(function($v){
+//             return Null;
+//         }, $this->getAttributes());
+        $obj->setValues($values);
         
         $obj->fillDefaultValues();
         
diff --git a/src/admin/common/models/column/float.php b/src/admin/common/models/column/float.php
new file mode 100644
index 0000000..be81642
--- /dev/null
+++ b/src/admin/common/models/column/float.php
@@ -0,0 +1,22 @@
+<?php
+
+// No direct access.
+defined('_JEXEC') or die;
+
+class CommonClubsModelColumnFloat extends AbstractCommonClubsModelColumn
+{
+    public function isSimpleType()
+    {
+        return true;
+    }
+    
+    public function getQuotedValue($q, $value)
+    {
+        if(is_null($value))
+            return 'NULL';
+        else
+            return (float) $value;
+    }
+    
+    
+}
diff --git a/src/admin/common/models/column/int.php b/src/admin/common/models/column/int.php
new file mode 100644
index 0000000..e7e265b
--- /dev/null
+++ b/src/admin/common/models/column/int.php
@@ -0,0 +1,22 @@
+<?php
+
+// No direct access.
+defined('_JEXEC') or die;
+
+class CommonClubsModelColumnInt extends AbstractCommonClubsModelColumn
+{
+    public function isSimpleType()
+    {
+        return true;
+    }
+    
+    public function getQuotedValue($q, $value)
+    {
+        if(is_null($value))
+            return 'NULL';
+        else
+            return (int) $value;
+    }
+    
+    
+}
diff --git a/src/admin/common/models/column/ref.php b/src/admin/common/models/column/ref.php
new file mode 100644
index 0000000..18b79e3
--- /dev/null
+++ b/src/admin/common/models/column/ref.php
@@ -0,0 +1,105 @@
+<?php
+
+// No direct access.
+defined('_JEXEC') or die;
+
+class WrongRefTypeException extends Exception
+{}
+
+class AssociatedObjectUnsavedException extends Exception
+{}
+
+class CommonClubsModelColumnRef extends AbstractCommonClubsModelColumn
+{
+    
+    protected $className;
+    
+    public function __construct($alias, $className, $required=true, $column=null)
+    {
+        parent::__construct($alias, $required, $column);
+        
+        if(empty($className))
+            throw new Exception('Classname must be non-empty.');
+        
+        $this->className = $className;
+    }
+    
+    public function isSimpleType()
+    {
+        return false;
+    }
+    
+    public function getQuotedValue($q, $value)
+    {
+        if(is_null($value))
+            return 'NULL';
+        else
+        {
+            if(! ( $value instanceof $this->className ) )
+                throw new WrongRefTypeException();
+            
+            $id = $value->getId();
+            if($id === 'new')
+                throw new AssociatedObjectUnsavedException();
+            
+            return $id;
+        }
+    }
+    
+    public function packValue($value)
+    {
+        if(is_null($value))
+            return null;
+        
+        if(! ($value instanceof $this->className) )
+            throw new WrongRefTypeException();
+        
+        $id = $value->getId();
+        
+        if($id === 'new')
+            throw new AssociatedObjectUnsavedException();
+        
+        return (int) $id;
+    }
+    
+    public function unpackValue($value)
+    {
+        if(empty($value))
+            return null;
+        
+        if(is_string($value) && preg_match('/^[0-9]+$/', $value))
+            $value = (int) $value;
+            
+        if(! is_int($value))
+            throw new Exception('Reference with non-integer value');
+            
+        $factoryName = $this->getFactoryNameOfClass($this->className); // XXX Use attribute?
+        $factory = new $factoryName();
+        return $factory->loadById($value);
+    }
+    
+    private const CLASSNAME_MAP = array(
+        
+    );
+    
+    /**
+     * @todo This must be done better and more cleanly
+     * @param string $className
+     * @return AbstractCommonClubsModelFactory
+     */
+    private function getFactoryNameOfClass($className)
+    {
+        if(empty(self::CLASSNAME_MAP[$className]))
+        {
+            $parts = array();
+            if(preg_match('/^CommonClubsModel(.*)/', $className, $parts))
+            {
+                return "CommonClubsModelFactory{$parts[1]}";
+            }
+            throw new Exception("Unknown mapping of class $className");
+        }
+        
+        return self::CLASSNAME_MAP[$className];
+    }
+    
+}
diff --git a/src/admin/common/models/column/string.php b/src/admin/common/models/column/string.php
new file mode 100644
index 0000000..fe2140f
--- /dev/null
+++ b/src/admin/common/models/column/string.php
@@ -0,0 +1,22 @@
+<?php
+
+// No direct access.
+defined('_JEXEC') or die;
+
+class CommonClubsModelColumnString extends AbstractCommonClubsModelColumn
+{
+    public function isSimpleType()
+    {
+        return true;
+    }
+
+    public function getQuotedValue($q, $value)
+    {
+        if(is_null($value))
+            return 'NULL';
+        else
+            return $q->q($value);
+    }
+
+    
+}
diff --git a/src/admin/common/models/factory/club.php b/src/admin/common/models/factory/club.php
index d3ee0c8..6331ad6 100644
--- a/src/admin/common/models/factory/club.php
+++ b/src/admin/common/models/factory/club.php
@@ -8,15 +8,15 @@ class CommonClubsModelFactoryClub extends AbstractCommonClubsModelFactory
     public function fetchAttributes()
     {
         return array(
-            'name'=>array(),
-            'address'=>array(),
-            'city'=>array(),
-            'homepage'=>array(),
-            'mail'=>array(),
-            'iban'=>array(),
-            'bic'=>array(),
-            'charitable'=>array('type'=>'int'),
-            'president'=>array('type'=>'ref', 'ref'=>'CommonClubsModelUser')
+            new CommonClubsModelColumnString('name'),
+            new CommonClubsModelColumnString('address'),
+            new CommonClubsModelColumnString('city'),
+            new CommonClubsModelColumnString('homepage'),
+            new CommonClubsModelColumnString('mail'),
+            new CommonClubsModelColumnString('iban'),
+            new CommonClubsModelColumnString('bic'),
+            new CommonClubsModelColumnInt('charitable'),
+            new CommonClubsModelColumnRef('president', 'CommonClubsModelUser')
         );
     }
 
diff --git a/src/admin/common/models/factory/place.php b/src/admin/common/models/factory/place.php
index fcae159..01b40c6 100644
--- a/src/admin/common/models/factory/place.php
+++ b/src/admin/common/models/factory/place.php
@@ -8,9 +8,9 @@ class CommonClubsModelFactoryPlace extends AbstractCommonClubsModelFactory
     public function fetchAttributes()
     {
         return array(
-            'name'=>array(),
-            'club'=>array('col'=>'clubid', 'type'=>'ref', 'ref'=>'CommonClubsModelClub'),
-            'area'=>array('type'=>'int', 'optional'=>true)
+            new CommonClubsModelColumnString('name'),
+            new CommonClubsModelColumnRef('club', 'CommonClubsModelClub', true, 'clubid'),
+            new CommonClubsModelColumnInt('area', false)
         );
     }
 
diff --git a/src/admin/common/models/factory/user.php b/src/admin/common/models/factory/user.php
index 5c55bea..437bd73 100644
--- a/src/admin/common/models/factory/user.php
+++ b/src/admin/common/models/factory/user.php
@@ -8,8 +8,8 @@ class CommonClubsModelFactoryUser extends AbstractCommonClubsModelFactory
     public function fetchAttributes()
     {
         return array(
-            'user'=>array(),
-            'name'=>array()
+            new CommonClubsModelColumnString('user'),
+            new CommonClubsModelColumnString('name')
         );
     }