diff --git a/src/Model.php b/src/Model.php
index 2a11136..01c00fa 100644
--- a/src/Model.php
+++ b/src/Model.php
@@ -4,9 +4,9 @@ namespace Krutush\Database;
 
 use Krutush\Database\DatabaseException;
 
-//TODO extends
-//TODO add model links
-
+/**
+ * Static is a table, Object is an row
+ */
 class Model{
     /** @var string */
     public const DATABASE = null;
@@ -21,19 +21,38 @@ class Model{
         'owner' => ['type' => 'int', 'foreign' => ['model' => UserModel::class, 'field' => 'id', 'on_delete' => 'cascade', 'on_update' => 'set null']]
     ]*/
 
+    /** @var array */ 
+    public const FOREIGNS = [];
+
     /** @var string */
     public const ID = 'id';
 
-    /** @var array
-     * @example ['id' => ['value' => 1, 'modified' => false]] */
+    /** 
+     * @var array
+     * @example ['id' => ['value' => 1, 'modified' => false]]
+     */
     protected $fields = [];
 
+    /**
+     * Use wildcard in select queries
+     * 
+     * @var boll
+     */
+    public const WILDCARD = true;
+
+    //Many be usefull  but not recommended
     public const FILTER = null;
-    public const INNER = null; //TODO: Manager OneToOne, OneToMany, ...
+    public const INNER = null;
     public const ORDER = null;
 
 
     /*=== MAGIC ===*/
+    /**
+     * Construct a model element with data
+     * 
+     * @param array $data to fill $fields
+     * @param boolean $useColumns use Column's name or Field's name
+     */
     public function __construct(array $data = [], bool $useColumns = false){
         foreach (static::getFields() as $field => $options) {
             $column = $useColumns ? static::getColumn($field) : $field;
@@ -43,13 +62,29 @@ class Model{
                 'modified' => false
             ];
         }
+        foreach(static::getForeigns() as $foreign => $options){
+            $this->fields[$foreign] = [
+                'modified' => false
+            ];
+        }
     }
 
     //MAYBE: Save on destroy
 
+    /**
+     * Get data without reflection (may became heavy)
+     * 
+     * @param string $field value's key or foreign's key if start with _
+     * @return mixed value, Model or null
+     */
     public function __get(string $field){
-		if(array_key_exists($field, $this->fields))
-            return $this->fields[$field]['value'];
+        if(strlen($field) > 0){
+            if($field[0] == '_')
+                return $this->get(substr($field, 1), true);
+
+            if(array_key_exists($field, $this->fields) && array_key_exists('value', $this->fields[$field]))
+                return $this->fields[$field]['value'];
+        }
 
 		$trace = debug_backtrace();
         trigger_error(
@@ -58,8 +93,26 @@ class Model{
             ' à la ligne ' . $trace[0]['line'],
             E_USER_NOTICE);
         return null;
-	}
+    }
 
+    public function __isset(string $field): bool{
+        if(strlen($field) > 0){
+            if($field[0] == '_')
+                return $this->haveForeignOptions(substr($field, 1));
+
+            if(array_key_exists($field, $this->fields) && array_key_exists('value', $this->fields[$field]))
+                return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Store data in $fields
+     * 
+     * @param string $field
+     * @param mixed $value
+     */
     public function __set(string $field, $value){
         if(array_key_exists($field, static::FIELDS)){
             $this->fields[$field] = [
@@ -74,10 +127,101 @@ class Model{
                 ' à la ligne ' . $trace[0]['line'],
                 E_USER_NOTICE);
         }
-	}
+    }
+    
+    /**
+     * Set foreign's data
+     *
+     * @param string $field
+     * @param Model|array|null $data
+     * @return void
+     */
+    public function set(string $field, $data){
+        if(!is_a($data, Model::class) && !is_array($data) && $data !== null)
+            throw new DatabaseException('Set data must be a Model, array of Model or null');
 
+        if((array_key_exists($field, static::FIELDS) && isset(static::getOptions($field)['foreign'])) || array_key_exists($field, static::FOREIGNS)){
+            $this->fields[$field]['foreign'] = $data;
+        }else{
+            $trace = debug_backtrace();
+            trigger_error(
+                'Propriété non-définie via set() : ' . $field .
+                ' dans ' . $trace[0]['file'] .
+                ' à la ligne ' . $trace[0]['line'],
+                E_USER_NOTICE);
+        }
+    }
+
+    /**
+     * Get foreign's data
+     *
+     * @param string $field
+     * @param boolean $load must load data if can't find it
+     * @return Model|array|null
+     */
+    public function get(string $field, bool $load = false){
+		if(array_key_exists($field, $this->fields)){
+            if(array_key_exists('foreign', $this->fields[$field]))
+                return $this->fields[$field]['foreign'];
+            else{
+                if($load){
+                    $foreign = static::getForeignOptions($field);
+
+                    if(!isset($foreign['model']))
+                        throw new DatabaseException('Any model for foreign in field '.$field);
+
+                    $model = $foreign['model'];
+
+                    if(!class_exists($model))
+                        throw new DatabaseException('Can\'t find class '.$model.' for foreign in field '.$field);
+
+                    $id = $this->{isset($foreign['for']) ? $foreign['for'] : $field};
+                    $where = $model::getColumn(isset($foreign['field']) ? $foreign['field'] : $model::ID).' = ?';
+
+                    $value = (isset($foreign['multiple']) && $foreign['multiple']) ? 
+                        $model::all([$id], $where):
+                        $model::first([$id], $where);
+                
+                    //MAYBE: Make nullable check
+
+                    $this->fields[$field]['foreign'] = $value;
+                    return $value;
+                }
+            }
+        }
+
+		$trace = debug_backtrace();
+        trigger_error(
+            'Propriété non-définie via get() : ' . $field .
+            ' dans ' . $trace[0]['file'] .
+            ' à la ligne ' . $trace[0]['line'],
+            E_USER_NOTICE);
+        return null;
+    }
+
+    /**
+     * Just get foreign's data or return null
+     *
+     * @param string $field
+     * @return Model|array|null
+     */
+    public function tryGet(string $field){
+		if(array_key_exists($field, $this->fields)){
+            if(array_key_exists('foreign', $this->fields[$field]))
+                return $this->fields[$field]['foreign'];
+        }
+
+        return null;
+    }
 
     /*=== CREATE ===*/
+    /**
+     * Create Model from PDOStatement
+     *
+     * @param \PDOStatement $row
+     * @param boolean $exception must throw exception ?
+     * @return self|null
+     */
     public static function fromRow(\PDOStatement $row, bool $exception = true): ?self{
         if($row->rowCount() < 1){
             if($exception)
@@ -89,6 +233,13 @@ class Model{
         return new static($data, true);
     }
 
+    /**
+     * Create Model array from PDOStatement
+     *
+     * @param \PDOStatement $row
+     * @param boolean $exception must throw exception ?
+     * @return array
+     */
     public static function fromRowAll(\PDOStatement $row, bool $exception = true): array{
         if($row->rowCount() < 1){
             if($exception)
@@ -103,7 +254,14 @@ class Model{
         return $res;
     }
 
-    public static function fromData($data, bool $useColumns = false): array{
+    /**
+     * Create Model array from data array
+     *
+     * @param array $data
+     * @param boolean $useColumns see __construct
+     * @return array
+     */
+    public static function fromData(array $data, bool $useColumns = false): array{
         $res = array();
         foreach($data as $element){
             $res[] = new static($element, $useColumns);
@@ -113,30 +271,112 @@ class Model{
 
 
     /*=== CONST ===*/
-    public static function getFields(bool $exception = false): array{
-        if(empty(static::$FIELDS) && $exception)
+    /**
+     * Same as static::FIELDS with empty check
+     *
+     * @param boolean $exception
+     * @return array
+     */
+    public static function getFields(bool $exception = true): array{
+        if(empty(static::FIELDS) && $exception)
             throw new DatabaseException('FIELDS not set');
         
         return static::FIELDS;
     }
 
+    /**
+     * Get params for a specific field
+     *
+     * @param string $field
+     * @return array
+     */
     public static function getOptions(string $field): array{
         $fields = static::getFields();
-        if(!isset($fields[$field]))
+        if(!isset($fields[$field])){
+            if(array_key_exists($field, static::FOREIGNS))
+                return static::FOREIGNS[$field];
+
             throw new DatabaseException('Can\'t find field : '.$field);
+        }
 
         return $fields[$field];
     }
 
+    /**
+     * Same as getFields for static::FOREIGNS
+     *
+     * @param boolean $exception
+     * @return array
+     */
+    public static function getForeigns(bool $exception = false): array{
+        if(empty(static::FOREIGNS) && $exception)
+            throw new DatabaseException('FOREIGNS not set');
+        
+        return static::FOREIGNS;
+    }
+
+    /**
+     * Get FIELDS foreign options or FOREIGNS options
+     *
+     * @param string $field
+     * @return array
+     */
+    public static function getForeignOptions(string $field): array{
+        $fields = static::getFields();
+        if(isset($fields[$field]) && isset($fields[$field]['foreign']))
+            return is_array($fields[$field]['foreign']) ? $fields[$field]['foreign'] : ['model' => $fields[$field]['foreign']];
+
+        $foreigns = static::getForeigns();
+        if(!isset($foreigns[$field]))
+            throw new DatabaseException('Not a foreign field');
+
+        return is_array($foreigns[$field]) ? $foreigns[$field] : ['model' => $foreigns[$field], 'for' => static::ID];
+    }
+
+    /**
+     * Check in field have FIELDS foreign options or FOREIGNS options
+     *
+     * @param string $field
+     * @return bool
+     */
+    public static function haveForeignOptions(string $field): bool{
+        $fields = static::getFields(false);
+        if($field == null)
+            return false;
+
+        if(isset($fields[$field]) && isset($fields[$field]['foreign']))
+            return true;
+
+        $foreigns = static::getForeigns();
+        return isset($foreigns[$field]);
+    }
+
+    /**
+     * Convert field to column
+     *
+     * @param string $field
+     * @return string
+     */
     public static function getColumn(string $field): string{
         $options = static::getOptions($field);
         return isset($options['column']) ? $options['column'] : $field;
     }
 
+    /**
+     * Get table ID (for find and findOrFail)
+     *
+     * @return string
+     */
     public static function getID(): string{
         return static::getColumn(static::ID);
     }
 
+    /**
+     * Get column's names
+     *
+     * @param boolean $sql add table name and quote
+     * @return array
+     */
     public static function getColumns(bool $sql = true): array{
         $fields = static::getFields();
         $columns = [];
@@ -147,6 +387,12 @@ class Model{
         return $columns;
     }
 
+    /**
+     * Same as getColumns but only with 'primary' => true fields
+     *
+     * @param boolean $sql add table name and quote
+     * @return array
+     */
     public static function getPrimaryColumns(bool $sql = true): array{
         $fields = static::getFields();
         $columns = [];
@@ -159,11 +405,17 @@ class Model{
         return $columns;
     }
 
+    /**
+     * Same as getColumns but only with 'modified' => true $this->fields
+     *
+     * @param boolean $sql add table name and quote
+     * @return array
+     */
     public function getModifiedColumns(bool $sql = true): array{
         $fields = static::getFields();
         $columns = [];
         foreach ($fields as $field => $options) {
-            if($this->fields[$field]['modified']){
+            if(isset($this->fields[$field]['modified']) && $this->fields[$field]['modified']){
                 $column = static::getColumn($field);
                 $columns[] = $sql ? '`'.static::TABLE.'`.`'.$column.'`' : $column;
             }
@@ -171,30 +423,52 @@ class Model{
         return $columns;
     }
 
+    /**
+     * Get fields values (reverse of static::fromData)
+     *
+     * @return array
+     */
     public function getValues(){
         $values = [];
         foreach ($this->fields as $field => $data) {
-            $values[] = $data['value'];
+            if(array_key_exists('value', $data))
+                $values[] = $data['value'];
         }
         return $values;
     }
 
+    /**
+     * Same as getValues but only with 'modified' => true $this->fields
+     *
+     * @return array
+     */
     public function getModifiedValues(){
         $values = [];
         foreach ($this->fields as $field => $data) {
-            if($data['modified'])
+            if(isset($data['modified']) && $data['modified'])
                 $values[] = $data['value'];
 
         }
         return $values;
     }
 
+    /**
+     * Remove all modified flags
+     *
+     * @return void
+     */
     public function unmodify(){
         foreach($this->fields as $field => $data){
-            $this->fields[$field]['modified'] = false;
+            if(isset($data['modified']))
+                $this->fields[$field]['modified'] = false;
         }
     }
 
+    /**
+     * Same as getValues but only with 'primary' => true fields
+     *
+     * @return array
+     */
     public function getPrimaryValues(){
         $values = [];
         foreach ($this->fields as $field => $data) {
@@ -204,7 +478,14 @@ class Model{
         return $values;
     }
 
-    protected static function convertField($data, $field){
+    /**
+     * Convert input to sql valid value
+     *
+     * @param mixed $data
+     * @param string $field
+     * @return mixed
+     */
+    protected static function convertField($data, string $field){
         $options = static::getOptions($field);
         if(is_null($data)){
             if(isset($options['not_null']) && $options['not_null'] == true)
@@ -246,10 +527,18 @@ class Model{
 
 
     /*=== QUERIES ===*/
+    /**
+     * Create Request\Select from Model
+     *
+     * @return Request\Select
+     */
     public static function select(): Request\Select{
         $req = Connection::get(static::DATABASE)
-            ->select(static::getColumns())
-            ->from(static::TABLE);
+            ->select()->from(static::TABLE);
+
+        if(!static::WILDCARD)
+            $req = $req->fields(static::getColumns());
+            
 
         if(static::INNER != null)
             $req = $req->join(static::INNER);
@@ -263,6 +552,11 @@ class Model{
         return static::prepare($req);
     }
 
+    /**
+     * Create Request\Insert (without data) from Model
+     *
+     * @return Request\Insert
+     */
     public static function insert(): Request\Insert{
         $req = Connection::get(static::DATABASE)
             ->insert(static::getColumns())
@@ -271,15 +565,25 @@ class Model{
         return $req;
     }
 
+    /**
+     * add values to insert and run it
+     *
+     * @param boolean $forceID must update id value
+     */
     public function runInsert(bool $forceID = true){
         $insert = static::insert();
         $res = $insert->run($this->getValues());
-        if($forceID)
+        if($forceID && static::ID != null)
             $this->{static::ID} = Connection::get(static::DATABASE)->getLastInsertID();
 
         return $res;
     }
 
+    /**
+     * Change value of modified fields in database
+     *
+     * @return Model
+     */
     public function runUpdate(){
         $req = Connection::get(static::DATABASE)
             ->update(static::getModifiedColumns())
@@ -290,6 +594,11 @@ class Model{
         return $this;
     }
 
+    /**
+     * Create Request\Create from Model
+     *
+     * @return Request\Create
+     */
     public static function create(): Request\Create{
         $req = Connection::get(static::DATABASE)
             ->create(static::TABLE);
@@ -336,15 +645,33 @@ class Model{
         return $req;
     }
 
-    public static function drop(){
+    /**
+     * Create Request\Drop from Model
+     *
+     * @return Request\Drop
+     */
+    public static function drop(): Request\Drop{
         return Connection::get(static::DATABASE)
             ->drop(static::TABLE);
     }
 
     /* Do advanced customuzation here */
-    protected static function prepare($req){ return $req; }
+    /**
+     * Modify default select request
+     *
+     * @param Request\Select $req
+     * @return Request\Select
+     */
+    protected static function prepare(Request\Select $req): Request\Select{ return $req; }
 
-    public static function runSelect(array $values = null, string $where = null){
+    /**
+     * Really used only for next functions
+     *
+     * @param array $values
+     * @param string $where
+     * @return PDOStatement
+     */
+    public static function runSelect(array $values = null, string $where = null): \PDOStatement{
         $req = static::select();
 
         if(isset($where))
@@ -353,26 +680,68 @@ class Model{
         return $req->run($values);
     }
 
+    /**
+     * Get first row than match $where with $values or null
+     *
+     * @param array $values
+     * @param string $where
+     * @return self|null
+     */
     public static function first(array $values = null, string $where = null): ?self{
         return static::fromRow(static::runSelect($values, $where), false);
     }
 
-    public static function firstOrFail(array $values = null, string $where = null): ?self{
+    /**
+     * Same as first but throw exception on null
+     *
+     * @param array $values
+     * @param string $where
+     * @return self
+     */
+    public static function firstOrFail(array $values = null, string $where = null): self{
         return static::fromRow(static::runSelect($values, $where));
     }
 
+    /**
+     * Get all rows than match $where with $values (may be empty)
+     *
+     * @param array $values
+     * @param string $where
+     * @return array
+     */
     public static function all(array $values = null, string $where = null): array{
         return static::fromRowAll(static::runSelect($values, $where), false);
     }
 
+    /**
+     * Same as all but throw exception on empty
+     *
+     * @param array $values
+     * @param string $where
+     * @return array
+     */
     public static function allOrFail(array $values = null, string $where = null): array{
         return static::fromRowAll(static::runSelect($values, $where));
     }
 
+    /**
+     * Check if at least one row exists
+     *
+     * @param array $values
+     * @param string $where
+     * @return boolean
+     */
     public static function exists(array $values = null, string $where = null): bool{
         return static::first($values, $where) !== null;
     }
 
+    /**
+     * Count row than match $where with $values
+     *
+     * @param array $values
+     * @param string $where
+     * @return integer
+     */
     public static function count(array $values = null, string $where = null): int{
         $req = static::select();
         $req->fields(['COUNT(*) as count']);
@@ -387,11 +756,100 @@ class Model{
         return $data['count'];
     }
 
+    /**
+     * Use static:ID to get row
+     *
+     * @param mixed $id int is a good idea
+     * @return self|null
+     */
     public static function find($id): ?self{
          return static::first(array($id), (static::getID().' = ?'));
     }
 
+    /**
+     * Same as find but throw exception on null
+     *
+     * @param mixed $id int is a good idea
+     * @return self
+     */
     public static function findOrFail($id): self{
          return static::firstOrFail(array($id), (static::getID().' = ?'));
     }
+
+    /**
+     * Preload foreign Model for a group of Models
+     *
+     * @param array $models
+     * @param string $field
+     * @return array updated models
+     */
+    public static function load(array $models, string $field): array{
+        if(!empty($models)){
+            $foreign = static::getForeignOptions($field);
+
+            if(!isset($foreign['model']))
+                throw new DatabaseException('Any model for foreign in field '.$field);
+
+            $model = $foreign['model'];
+
+            if(!class_exists($model))
+                throw new DatabaseException('Can\'t find class '.$model.' for foreign in field '.$field);
+
+            $ids = [];
+            foreach ($models as $current) {
+                $ids[] = $current->{isset($foreign['for']) ? $foreign['for'] : $field};
+            }
+            $ids = array_unique($ids);
+            $foreigns = [];
+            foreach($model::all($ids, $model::getColumn(isset($foreign['field']) ? $foreign['field'] : $model::ID).' IN ( '.str_repeat('?, ', count($ids)-1).'? )') as $current){
+                $cid = $current->{isset($foreign['field']) ? $foreign['field'] : $model::ID};
+                if(isset($foreign['multiple']) && $foreign['multiple'])
+                    $foreigns[$cid][] = $current;
+                else
+                    $foreigns[$cid] = $current;
+            }
+
+            foreach ($models as &$current) {
+                $id = $current->{isset($foreign['for']) ? $foreign['for'] : $field};
+                if(isset($foreigns[$id]))
+                    $current->set($field, $foreigns[$id]);
+                else if(!isset($foreign['nullable']) || !$foreign['nullable'])
+                    throw new DatabaseException('Null foreign model');
+                else
+                    $current->set($field, null);
+            }
+        }
+
+        return $models;
+    }
+
+    /**
+     * Preload multiple foreign Model with recursivity for a group of Models
+     *
+     * @param array $models
+     * @param array $fields
+     * @return array updated models
+     */
+    public static function loads(array $models, array $fields): array{
+        foreach($fields as $field => $data){
+            $subfields = [];
+            if(is_array($data)){
+                $subfields = $data;
+            }else{
+                $field = $data;
+            }
+            $models = static::load($models, $field);
+            if(!empty($subfields)){
+                $submodels = [];
+                foreach($models as $model){
+                    if($model->tryGet($field) != null)
+                        $submodels[] = $model->get($field);
+                }
+                if(!empty($submodels)){
+                    $submodels[0]::loads($submodels, $subfields);
+                }
+            }
+        }
+        return $models;
+    }
 }
\ No newline at end of file