diff --git a/src/Annotation/Property/Field/Id.php b/src/Annotation/Property/Field/Id.php
index 931b0ae..277373c 100644
--- a/src/Annotation/Property/Field/Id.php
+++ b/src/Annotation/Property/Field/Id.php
@@ -11,7 +11,7 @@ class Id extends \Ulmus\Annotation\Property\Field {
         $this->attributes['primary_key'] = true;
         $this->attributes['auto_increment'] = true;
         
-        parent::__construct('int');
+        parent::__construct('bigint');
     }
 
 }
diff --git a/src/Annotation/Property/Filter.php b/src/Annotation/Property/Filter.php
index d1f4eb9..e25f831 100644
--- a/src/Annotation/Property/Filter.php
+++ b/src/Annotation/Property/Filter.php
@@ -12,4 +12,4 @@ class Filter implements \Ulmus\Annotation\Annotation {
             $this->method = $method;
         }
     }
-}
+}
\ No newline at end of file
diff --git a/src/Annotation/Property/Where.php b/src/Annotation/Property/Where.php
index e0e922d..622179c 100644
--- a/src/Annotation/Property/Where.php
+++ b/src/Annotation/Property/Where.php
@@ -11,8 +11,10 @@ class Where implements \Ulmus\Annotation\Annotation {
     public $value;
     
     public string $operator;
+
+    public string $condition;
     
-    public function __construct(/* stringable */ $field = null, $value = null, ? string $operator = null)
+    public function __construct(? string $field = null, $value = null, ? string $operator = null, ? string $condition = null)
     {
         if ( $field !== null ) {
             $this->field = $field;
@@ -22,11 +24,7 @@ class Where implements \Ulmus\Annotation\Annotation {
             $this->value = $value;
         }
         
-        if ( $operator !== null ) {
-            $this->operator = $operator;
-        }
-        else {
-            $this->operator = Query\Where::OPERATOR_EQUAL;
-        }
+        $this->operator = $operator !== null ? $operator : Query\Where::OPERATOR_EQUAL; 
+        $this->condition = $condition !== null ? $condition : Query\Where::CONDITION_AND; 
     }
 }
diff --git a/src/EntityCollection.php b/src/EntityCollection.php
index e66440f..e490113 100644
--- a/src/EntityCollection.php
+++ b/src/EntityCollection.php
@@ -25,12 +25,12 @@ class EntityCollection extends \ArrayObject {
             }
         }
     }
-
-    public function filtersCollection(Callable $callback, bool $yieldValueOnly = false, bool $replaceCollection = false) : self
+        
+    public function filtersCollection(Callable $callback, bool $replaceCollection = false) : self
     {
         $collection = new static();
-
-        foreach($this->filters($callback, $yieldValueOnly) as $item) {
+        
+        foreach($this->filters($callback, true) as $item) {
             $collection->append($item);
         }
 
@@ -77,8 +77,15 @@ class EntityCollection extends \ArrayObject {
 
         return $removed;
     }
-
-    public function search($value, string $field, bool $strict = true) : Generator
+    
+    public function clear() : self
+    {
+        $this->exchangeArray([]);
+        
+        return $this;
+    }
+    
+    public function search($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;
@@ -105,7 +112,12 @@ class EntityCollection extends \ArrayObject {
 
         return $obj;
     }
-
+    
+    public function searchInstances(string $className) : self
+    {
+        return $this->filtersCollection(fn($obj) => is_a($obj, $className));
+    }
+    
     public function column($field, bool $unique = false) : array
     {
         $list = [];
@@ -117,9 +129,9 @@ class EntityCollection extends \ArrayObject {
             else {
                 $value = $item->$field;
             }
-
-            if ($unique && in_array($value, $list)) {
-                break;
+            
+            if ($unique && in_array($value, $list, true)) {
+                continue;
             }
 
             $list[] = $value;
@@ -249,15 +261,22 @@ class EntityCollection extends \ArrayObject {
             parent::append($value);
         }
     }
-
-    public function mergeWith( /*array|EntityCollection*/ $datasets ) : self
+    
+    public function mergeWith(... $datasets) : self
     {
-        if ( is_object($datasets) ) {
-            $datasets = $datasets->getArrayCopy();
+        $list = [];
+        
+        foreach($datasets as $dataset) {
+            if ( is_object($dataset) ) {
+                $list = array_merge($dataset->getArrayCopy(), $list);
+            }
+            else {
+                $list = array_merge($dataset, $list);
+            }
         }
-
-        $this->exchangeArray( array_merge( $this->getArrayCopy(), $datasets ) );
-
+        
+        $this->exchangeArray( array_merge( $this->getArrayCopy(), $list ) );
+        
         return $this;
     }
 
@@ -287,4 +306,16 @@ class EntityCollection extends \ArrayObject {
 
         return $this;
     }
+
+    public function rsort(callable $callback, $function = "uasort") : self
+    {
+        $this->sort(...func_get_args());
+
+        return $this->reverse();
+    }
+
+    public function reverse() : self
+    {
+        return $this->replaceWith(array_reverse($this->getArrayCopy()));;
+    }
 }
diff --git a/src/EntityTrait.php b/src/EntityTrait.php
index bb8ac09..e7e2e74 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, Filter, On };
+use Ulmus\Annotation\Property\{ Field, Filter, Relation, OrderBy, Where, Join, Virtual, On, };
 use Ulmus\Annotation\Property\Field\{ Id, ForeignKey, CreatedAt, UpdatedAt, Datetime as DateTime, Date, Time, };
 
 trait EntityTrait {
@@ -67,11 +67,10 @@ trait EntityTrait {
                 $filters = $entityResolver->searchFieldAnnotationList($name, new Filter() );
 
                 $baseEntity = $relation->entity ?? $relation->bridge ?? $entityResolver->properties[$name]['type'];
-
                 $repository = $baseEntity::repository()->open();
 
-                foreach ($where as $condition) {
-                    $repository->where($condition->field, is_callable($condition->value) ? call_user_func_array($condition->value, [$this]) : $condition->value, $condition->operator, $condition->condition);
+                foreach($where as $condition) {
+                    $repository->where($condition->field, is_callable($condition->value) ? call_user_func_array($condition->value, [ $this ]) : $condition->value, $condition->operator, $condition->condition);
                 }
 
                 $repository->close();
@@ -79,6 +78,14 @@ trait EntityTrait {
                 foreach ($order as $item) {
                     $repository->orderBy($item->field, $item->order);
                 }
+                                
+                $applyFilter = function($repository) use ($filters, $name) {
+                    foreach($filters as $filter) {
+                        $repository = call_user_func_array([ $this, $filter->method ], [ $repository, $name ]);
+                    }
+                    
+                    return $repository;
+                };
 
                 $field = $relation->key;
 
@@ -112,6 +119,7 @@ trait EntityTrait {
                         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([$applyFilter($repository), $relation->function]);
diff --git a/src/QueryBuilder.php b/src/QueryBuilder.php
index 40fcf00..23d50c6 100644
--- a/src/QueryBuilder.php
+++ b/src/QueryBuilder.php
@@ -66,7 +66,7 @@ class QueryBuilder
             if ( $schema ) {
                 $table = "$schema.$table";
             }
-
+            
             if ( $database ) {
                 $table = "$database.$table";
             }
@@ -329,7 +329,7 @@ class QueryBuilder
             if ( $schema ) {
                 $table = "$schema.$table";
             }
-
+            
             if ( $database ) {
                 $table = "$database.$table";
             }
diff --git a/src/Repository.php b/src/Repository.php
index 73931d4..db8e757 100644
--- a/src/Repository.php
+++ b/src/Repository.php
@@ -177,6 +177,64 @@ class Repository
         }
     }
 
+    public function loadCollectionRelation(EntityCollection $collection, /*array|string*/ $fields) : void
+    {
+        foreach((array) $fields as $name) {
+            if ( null !== ( $relation = $this->entityResolver->searchFieldAnnotation($name, new Annotation\Property\Relation() ) ) ) {
+                $relationType = strtolower(str_replace(['-', '_', ' '], '', $relation->type));
+
+                $order = $this->entityResolver->searchFieldAnnotationList($name, new Annotation\Property\OrderBy() );
+                $where = $this->entityResolver->searchFieldAnnotationList($name, new Annotation\Property\Where() );
+
+                $baseEntity = $relation->entity ?? $relation->bridge ?? $this->entityResolver->properties[$name]['type'];
+                $baseEntityResolver = $baseEntity::resolveEntity();
+
+                $property = ( $baseEntityResolver->field($relation->foreignKey, 01, false) ?: $baseEntityResolver->field($relation->foreignKey, 02) )['name'];
+                $entityProperty = ( $this->entityResolver->field($relation->key, 01, false) ?: $this->entityResolver->field($relation->key, 02) )['name'];
+
+                $repository = $baseEntity::repository();
+
+                foreach($where as $condition) {
+                    $repository->where($condition->field, is_callable($condition->value) ? call_user_func_array($condition->value, [ $this ]) : $condition->value, $condition->operator, $condition->condition);
+                }
+
+                foreach($order as $item) {
+                    $repository->orderBy($item->field, $item->order);
+                }
+
+                $field = $relation->key;
+
+                $values = [];
+
+                $key = is_object($relation->foreignKey) ? $relation->foreignKey : $baseEntity::field($relation->foreignKey);
+
+                foreach($collection as $item) {
+                    $values[] = is_callable($field) ? $field($item) : $item->$entityProperty;
+                }
+
+                $repository->where($key, $values);
+
+                switch( $relationType ) {
+                    case 'onetoone':
+                        $results = call_user_func([ $repository, "loadOne" ]);
+                        $item->$name = $results ?: new $baseEntity();
+                        
+                        break;
+                        
+                    case 'onetomany':
+                        $results = call_user_func([ $repository, $relation->function ]);
+                        
+                        foreach($collection as $item) {
+                            $item->$name = $baseEntity::entityCollection();
+                            $item->$name->mergeWith( $results->filtersCollection(fn($e) => $e->$property === $item->$entityProperty ) );
+                        }
+                        
+                        break;
+                }
+            }
+        }
+    }
+    
     public function truncate(? string $table = null, ? string $alias = null, ? string $schema = null) : self
     {
         $schema = $schema ?: $this->entityResolver->schemaName();
diff --git a/src/Repository/ConditionTrait.php b/src/Repository/ConditionTrait.php
index 3c681e0..d8eee98 100644
--- a/src/Repository/ConditionTrait.php
+++ b/src/Repository/ConditionTrait.php
@@ -25,9 +25,9 @@ trait ConditionTrait
         return $this;
     }
 
-    public function where($field, $value, string $operator = Query\Where::OPERATOR_EQUAL) : self
+    public function where($field, $value, string $operator = Query\Where::OPERATOR_EQUAL, $condition = Query\Where::CONDITION_AND) : self
     {
-        $this->queryBuilder->where($field, $value, $operator, Query\Where::CONDITION_AND);
+        $this->queryBuilder->where($field, $value, $operator, $condition);
         
         return $this;
     }
@@ -67,9 +67,9 @@ trait ConditionTrait
         return $this;
     }
 
-    public function having($field, $value, string $operator = Query\Where::OPERATOR_EQUAL) : self
+    public function having($field, $value, string $operator = Query\Where::OPERATOR_EQUAL, $condition = Query\Where::CONDITION_AND) : self
     {
-        $this->queryBuilder->having($field, $value, $operator, Query\Where::CONDITION_AND);
+        $this->queryBuilder->having($field, $value, $operator, $condition);
         
         return $this;
     }