diff --git a/src/Annotation/Property/Field.php b/src/Annotation/Property/Field.php
index 1a4efcc..05938ca 100644
--- a/src/Annotation/Property/Field.php
+++ b/src/Annotation/Property/Field.php
@@ -7,15 +7,13 @@ class Field implements \Ulmus\Annotation\Annotation {
     public string $type;
 
     public string $name;
-    
-    # public string $column;
-    
+        
     public int $length;
 
     public array $attributes = [];
 
     public bool $nullable = false;
-
+    
     public function __construct(? string $type = null, ? int $length = null)
     {
         if ( $type !== null ) {
diff --git a/src/Annotation/Property/Virtual.php b/src/Annotation/Property/Virtual.php
new file mode 100644
index 0000000..e6a1d78
--- /dev/null
+++ b/src/Annotation/Property/Virtual.php
@@ -0,0 +1,7 @@
+<?php
+
+namespace Ulmus\Annotation\Property;
+
+class Virtual extends Field {
+    public Closure $closure;
+}
diff --git a/src/Common/EntityResolver.php b/src/Common/EntityResolver.php
index 500eebf..ec72765 100644
--- a/src/Common/EntityResolver.php
+++ b/src/Common/EntityResolver.php
@@ -5,6 +5,7 @@ namespace Ulmus\Common;
 use Ulmus\Annotation\Annotation,
     Ulmus\Annotation\Classes\Table,
     Ulmus\Annotation\Property\Field,
+    Ulmus\Annotation\Property\Virtual,
     Ulmus\Annotation\Property\Relation;
 
 class EntityResolver {
@@ -50,13 +51,17 @@ class EntityResolver {
         return null;
     }
 
-    public function fieldList($fieldKey = self::KEY_ENTITY_NAME) : array
+    public function fieldList($fieldKey = self::KEY_ENTITY_NAME, bool $skipVirtual = false) : array
     {
         $fieldList = [];
         
         foreach($this->properties as $item) {
             foreach($item['tags'] ?? [] as $tag) {
                 if ( $tag['object'] instanceof Field ) {
+                    if ( $skipVirtual && ($tag['object'] instanceof Virtual )) {
+                        break;
+                    }
+                    
                     switch($fieldKey) {
                         case static::KEY_ENTITY_NAME:
                             $key = $item['name'];
diff --git a/src/Common/PdoObject.php b/src/Common/PdoObject.php
index ba20a73..3023b62 100644
--- a/src/Common/PdoObject.php
+++ b/src/Common/PdoObject.php
@@ -6,9 +6,13 @@ use PDO,
     PDOStatement;
 
 class PdoObject extends PDO {
+    
+    public static ? string $dump = null;
 
     public function select(string $sql, array $parameters = []): PDOStatement 
     {
+        static::$dump && call_user_func_array(static::$dump, [ $sql, $parameters ]);
+        
         try {
             if (false !== ( $statement = $this->prepare($sql) )) {
                 $statement = $this->execute($statement, $parameters, false);
@@ -24,6 +28,8 @@ class PdoObject extends PDO {
 
     public function runQuery(string $sql, array $parameters = []): ? PDOStatement 
     {
+        static::$dump && call_user_func_array(static::$dump, [ $sql, $parameters ]);
+        
         try {
             if (false !== ( $statement = $this->prepare($sql) )) {
                 return $this->execute($statement, $parameters, true);
@@ -62,7 +68,9 @@ class PdoObject extends PDO {
             throw $e;
         }
         catch (\Throwable $e) {
-            debogueur($statement, $parameters, $commit);
+            if ( function_exists("debogueur") ) {
+                debogueur($statement, $parameters, $commit);
+            }
             
             throw $e;
         }
diff --git a/src/EntityCollection.php b/src/EntityCollection.php
index 3e11387..5f94cfe 100644
--- a/src/EntityCollection.php
+++ b/src/EntityCollection.php
@@ -8,7 +8,7 @@ class EntityCollection extends \ArrayObject {
     
     public ? string $entityClass = null;
     
-    public function filters(Callable $callback) : Generator
+    public function filters(Callable $callback, bool $yieldValueOnly = false) : Generator
     {
         $idx = 0;
         
@@ -16,31 +16,41 @@ class EntityCollection extends \ArrayObject {
             if ( $callback($item, $key, $idx) ) {
                 $idx++;
                 
-                yield $key => $item;
+                if ( $yieldValueOnly ) {
+                    yield $item;
+                }
+                else {
+                    yield $key => $item;
+                }
             }
         }
     }
         
-    public function filtersCollection(Callable $callback) : self
+    public function filtersCollection(Callable $callback, bool $yieldValueOnly = false, bool $replaceCollection = false) : self
     {
         $collection = new static();
         
-        foreach($this->filters($callback) as $item) {
+        foreach($this->filters($callback, $yieldValueOnly) as $item) {
             $collection->append($item);
         }
         
-        return $collection;
+        if ($replaceCollection) {
+            $this->exchangeArray(array_values($collection->getArrayCopy()));
+            
+            return $this;
+        }
+        else {
+            return $collection;
+        }
     }
         
-    public function iterate(Callable $callback) : array
+    public function iterate(Callable $callback) : self
     {
-        $results = [];
-        
         foreach($this as $item) {
-            $results[] = $callback($item);
+            $callback($item);
         }
         
-        return $results;
+        return $this;
     }
     
     public function removeOne($value, string $field, bool $strict = true) : ? object
@@ -68,6 +78,13 @@ class EntityCollection extends \ArrayObject {
         return $removed;
     }
     
+    public function search($value, string $field, bool $strict = true) : Generator 
+    {
+        foreach($this->filters(fn($v) => $strict ? $v->$field === $value : $v->$field == $value) as $key => $item) {
+            yield $key => $item;
+        }
+    }
+    
     public function searchOne($value, string $field, bool $strict = true) : ? object 
     {
         # Returning first value only
@@ -78,24 +95,83 @@ class EntityCollection extends \ArrayObject {
         return null;
     }
     
-    public function search($value, string $field, bool $strict = true) : Generator 
+    public function searchAll($value, string $field, bool $strict = true) : self
     {
-        foreach($this->filters(fn($v) => $strict ? $v->$field === $value : $v->$field == $value) as $key => $item) {
-            yield $key => $item;
+        $obj = new static();
+        
+        foreach($this->search($value, $field, $strict) as $item) {
+            $obj->append($item);
         }
+        
+        return $obj;
     }
     
-    public function column($field) : array
+    public function column($field, bool $unique = false) : array
     {
         $list = [];
         
         foreach($this as $item) {
-            $list[] = $item->$field;
+            if ( is_callable($field) ) {
+                $value = call_user_func_array($field, [ $item ]);
+            }
+            else {
+                $value = $item->$field;
+            }
+            
+            if ($unique && in_array($value, $list)) {
+                break;
+            }
+            
+            $list[] = $value;
         }
         
         return $list;
     }
     
+    public function unique(/*stringable|callable */ $field, bool $strict = false) : self
+    {
+        $list = [];
+        $obj = new static();
+        
+        foreach($this as $item) {
+            if ( $field === null) {
+                $value = $this;
+            }
+            if ( is_callable($field) ) {
+                $value = call_user_func_array($field, [ $item ]);
+            }
+            else {
+                $value = $item->$field;
+            }
+            
+            if ( ! in_array($value, $list, $strict) ) {
+                $list[] = $value;
+                
+                $obj->append($item);
+            }   
+        }
+        
+        return $obj;
+    }
+    
+    public function first() : ? object
+    {
+        foreach($this as $item) {
+            return $item;
+        }
+        
+        return null;
+    }
+
+    public function last() : ? object
+    {
+        foreach($this as $item) {
+            $return = $item;
+        }
+        
+        return $return ?? null;
+    }
+    
     public function buildArray(string $keyColumn, /* string|callable|null */ $value = null) : array
     {
         $list = [];
@@ -143,7 +219,7 @@ class EntityCollection extends \ArrayObject {
         return $list;
     }
         
-    public function fromArray(array $datasets, ? string $entityClass = null) : self 
+    public function fromArray(array $datasets, ? string /*stringable*/ $entityClass = null) : self 
     {
         if ( ! ($this->entityClass || $entityClass) ) {
             throw new \Exception("An entity class name must be provided to be instanciated and populated before insertion into this collection.");
@@ -168,4 +244,31 @@ class EntityCollection extends \ArrayObject {
         
         return $this;
     }
+    
+    public function replaceWith( /*array|EntityCollection*/ $datasets ) : self
+    {
+        if ( is_object($datasets) ) {
+            $datasets = $datasets->getArrayCopy();
+        }
+        
+        $this->exchangeArray( $datasets );
+        
+        return $this;
+    }
+    
+    public function randomize() : self
+    {
+        $arr = $this->getArrayCopy();
+        shuffle($arr);
+        $this->exchangeArray($arr);
+        
+        return $this;
+    }
+    
+    public function sort(callable $callback, $function = "uasort") : self
+    {
+        call_user_func_array([ $this, $function ], [ $callback ]);
+
+        return $this;
+    }
 }
diff --git a/src/EntityTrait.php b/src/EntityTrait.php
index 4521f5f..51acd5f 100644
--- a/src/EntityTrait.php
+++ b/src/EntityTrait.php
@@ -8,7 +8,7 @@ use Ulmus\Repository,
     Ulmus\Common\EntityField;
 
 use Ulmus\Annotation\Classes\{ Method, Table, Collation, };
-use Ulmus\Annotation\Property\{ Field, Relation, OrderBy, Where, Join };
+use Ulmus\Annotation\Property\{ Field, Relation, OrderBy, Where, Join, Virtual };
 use Ulmus\Annotation\Property\Field\{ Id, ForeignKey, CreatedAt, UpdatedAt, };
 
 trait EntityTrait {
@@ -71,7 +71,7 @@ trait EntityTrait {
                     $repository = $baseEntity->repository();
 
                     foreach($where as $condition) {
-                        $repository->where($condition->field, $condition->value, $condition->operator);
+                        $repository->where($condition->field, is_callable($condition->value) ? $f = call_user_func_array($condition->value, [ $this ]) : $condition->value, $condition->operator);
                     }
 
                     foreach($order as $item) {
@@ -82,9 +82,11 @@ trait EntityTrait {
                 }
 
                 switch( $relationType ) {
-                    case 'onetoone':                    
-                        $repository->where( is_object($relation->foreignKey) ? $relation->foreignKey : $baseEntity->field($relation->foreignKey), $this->$field );
-
+                    case 'onetoone':       
+                        if ($relation->foreignKey) {             
+                            $repository->where( is_object($relation->foreignKey) ? $relation->foreignKey : $baseEntity->field($relation->foreignKey), is_callable($field) ? $field($this) : $this->$field );
+                        }
+                        
                         $this->eventExecute(Event\EntityRelationLoadInterface::class, $name, $repository);
                         
                         $result = call_user_func([$repository, $relation->function]);
@@ -96,7 +98,9 @@ trait EntityTrait {
                         return $this->$name = $result[0];
 
                     case 'onetomany':
-                        $repository->where( is_object($relation->foreignKey) ? $relation->foreignKey : $baseEntity->field($relation->foreignKey), $this->$field );
+                        if ($relation->foreignKey) {
+                            $repository->where( is_object($relation->foreignKey) ? $relation->foreignKey : $baseEntity->field($relation->foreignKey), is_callable($field) ? $field($this) : $this->$field );
+                        }
                         $this->eventExecute(Event\EntityRelationLoadInterface::class, $name, $repository);
 
                         return $this->$name = call_user_func([$repository, $relation->function]);
@@ -186,12 +190,12 @@ trait EntityTrait {
     /**
      * @Ignore
      */
-    public function entityFillFromDataset(iterable $dataset) : self
+    public function entityFillFromDataset(iterable $dataset, bool $isLoadedDataset = false) : self
     {
         $loaded = $this->isLoaded();
         
         $entityResolver = $this->resolveEntity();
-        
+
         foreach($dataset as $key => $value) {
             $field = $entityResolver->field(strtolower($key), EntityResolver::KEY_COLUMN_NAME, false) ?? null;
             
@@ -235,7 +239,7 @@ trait EntityTrait {
             }
             
             # Keeping original data to diff on UPDATE query
-            if ( ! $loaded ) {
+            if ( ! $loaded || $isLoadedDataset ) {
                 #if ( $field !== null ) {
                 #    $annotation = $entityResolver->searchFieldAnnotation($field['name'], new Field() );
                 #    $this->entityLoadedDataset[$annotation ? $annotation->name : $field['name']] = $dataset;       # <--------- THIS TO FIX !!!!!!
@@ -268,7 +272,7 @@ trait EntityTrait {
         
         $entityResolver = $this->resolveEntity();
         
-        foreach($entityResolver->fieldList() as $key => $field) {
+        foreach($entityResolver->fieldList(Common\EntityResolver::KEY_ENTITY_NAME, true) as $key => $field) {
             $annotation = $entityResolver->searchFieldAnnotation($key, new Field() );
 
             if ( isset($this->$key) ) { 
@@ -292,7 +296,6 @@ trait EntityTrait {
             }
         }
         
-        # @TODO Must fix recursive bug !
         if ($includeRelations) {
             foreach($entityResolver->properties as $name => $field){
                 $relation = $entityResolver->searchFieldAnnotation($name, new Relation() );
@@ -303,13 +306,13 @@ trait EntityTrait {
                             $list = [];
                             
                             foreach($value as $entity) {
-                                $list[] = $entity->entityGetDataset(true);
+                                $list[] = $entity->entityGetDataset(false);
                             }
                             
                             $dataset[$name] = $list;
                         }
                         elseif ( is_object($value) ) {
-                            $dataset[$name] = $value->entityGetDataset(true);
+                            $dataset[$name] = $value->entityGetDataset(false);
                         }
                     }
                 }
diff --git a/src/Query/Where.php b/src/Query/Where.php
index 78ee819..7b24b73 100644
--- a/src/Query/Where.php
+++ b/src/Query/Where.php
@@ -36,7 +36,7 @@ class Where extends Fragment {
         $this->condition = $condition;
         $this->parent = $queryBuilder->where ?? null;
     }
-
+    
     public function add($field, $value, string $operator, string $condition, bool $not = false) : self
     {
         $this->conditionList[] = [
diff --git a/src/QueryBuilder.php b/src/QueryBuilder.php
index c158d9d..2c4fc22 100644
--- a/src/QueryBuilder.php
+++ b/src/QueryBuilder.php
@@ -29,6 +29,23 @@ class QueryBuilder
 
     protected array $queryStack = [];
 
+    public function __clone() 
+    {
+        if ($this->where ?? false) {
+            #$this->where = clone $this->where;
+            #$this->where->queryBuilder = $this;
+        }
+        
+        if ($this->having ?? false) {
+            #$this->having = clone $this->having;
+            #$this->having->queryBuiler = $this;
+        }
+        
+        if ($this->parent ?? false) {
+            #$this->parent = clone $this->parent;
+        }
+    }
+    
     public function select($field) : self
     {
         if ( null !== ( $select = $this->getFragment(Query\Select::class) ) ) {
diff --git a/src/Repository.php b/src/Repository.php
index b093bbb..2c019b3 100644
--- a/src/Repository.php
+++ b/src/Repository.php
@@ -29,6 +29,11 @@ class Repository
         $this->adapter = $adapter ?? $this->entityResolver->databaseAdapter() ?? Ulmus::$defaultAdapter;
         $this->queryBuilder = new QueryBuilder();
     }
+    
+    public function __clone() 
+    {
+        #$this->queryBuilder = clone $this->queryBuilder;
+    }
 
     public function loadOne() : ? object
     {
@@ -137,9 +142,11 @@ class Repository
             if ( ( 0 !== $statement->lastInsertId ) && 
                ( null !== $primaryKeyDefinition )) {
                 $pkField = key($primaryKeyDefinition);
-                $entity->$pkField = $statement->lastInsertId;
+                $dataset[$pkField] = $statement->lastInsertId;
             }
             
+            $entity->entityFillFromDataset($dataset, true);
+            
             return true;
         }
         else {
@@ -153,6 +160,7 @@ class Repository
                 $this->where($pkFieldName, $dataset[$pkFieldName]);
 
                 $update = $this->updateSqlQuery($diff)->runQuery();
+                $entity->entityFillFromDataset($dataset);
                 
                 return $update ? (bool) $update->rowCount() : false;
             }
@@ -199,7 +207,7 @@ class Repository
         }
     }
 
-    public function select($fields) : self
+    public function select(/*array|Stringable*/ $fields) : self
     {
         $this->queryBuilder->select($fields);
         
@@ -313,6 +321,14 @@ class Repository
         return $this;
     }
 
+    # @UNTESTED
+    public function randomizeOrder() : self
+    {
+        $this->queryBuilder->orderBy(Common\Sql::function('RAND', Sql::identifier('CURDATE()+0')));
+        
+        return $this;
+    }
+    
     public function orders(array $orderList) : self
     {
         foreach($orderList as $field => $direction) {
@@ -361,7 +377,7 @@ class Repository
         return $this->where($primaryKeyField[$pkField]->name ?? $pkField, $value);
     }
  
-    public function withJoin(/*string|array*/ $fields) : self
+    public function withJoin(/*stringable|array*/ $fields) : self
     {
         $resolvedEntity = Ulmus::resolveEntity($this->entityClass);
         
@@ -374,7 +390,7 @@ class Repository
                 $alias = $join->alias ?? $item;
                 $entity = $join->entity ?? $resolvedEntity->properties[$item]['type'];
                 
-                foreach($entity::resolveEntity()->fieldList(Common\EntityResolver::KEY_COLUMN_NAME) as $key => $field) {
+                foreach($entity::resolveEntity()->fieldList(Common\EntityResolver::KEY_COLUMN_NAME, true) as $key => $field) {
                     $this->select("$alias.$key as {$alias}\${$field['name']}");
                 }
                 
@@ -397,17 +413,19 @@ class Repository
         $wheres = $searchRequest->wheres();
         $groups = $searchRequest->groups();
         
-        $searchRequest->count = $searchRequest->skipCount ? 0 : $searchRequest->filter( clone $this )
+        $searchRequest->filter( $this )
             ->wheres($wheres, Query\Where::OPERATOR_EQUAL, Query\Where::CONDITION_AND)
             ->likes($likes, Query\Where::CONDITION_OR)
-            ->groups($groups)
-            ->count();
+            ->groups($groups);
         
-        return $searchRequest->filter($this)
+        $searchRequest->count = $searchRequest->skipCount ? 0 : (clone $this)->count();
+        
+        return $searchRequest
+            ->filter($this)
             ->wheres($wheres, Query\Where::OPERATOR_EQUAL, Query\Where::CONDITION_AND)
             ->likes($likes, Query\Where::CONDITION_OR)
-            ->orders($searchRequest->orders())
             ->groups($groups)
+            ->orders($searchRequest->orders())
             ->offset($searchRequest->offset())
             ->limit($searchRequest->limit());
     }
@@ -447,6 +465,13 @@ class Repository
         return Ulmus::runQuery($this->queryBuilder, $this->adapter);
     }
     
+    public function resetQuery() : self
+    {
+        $this->queryBuilder->reset();
+        
+        return $this;
+    }
+    
     protected function insertSqlQuery(array $dataset) : self
     {
         if ( null === $this->queryBuilder->getFragment(Query\Insert::class) ) {
@@ -505,9 +530,9 @@ class Repository
 
     }
     
-    public function instanciateEntityCollection() : EntityCollection
+    public function instanciateEntityCollection(...$arguments) : EntityCollection
     {
-        return $this->entityClass::entityCollection();
+        return $this->entityClass::entityCollection(...$arguments);
     }
     
     public function escapeTable(string $identifier) : string