diff --git a/src/Common/PdoObject.php b/src/Common/PdoObject.php
index e160d6b..fc6c33e 100644
--- a/src/Common/PdoObject.php
+++ b/src/Common/PdoObject.php
@@ -8,6 +8,8 @@ use PDO,
 class PdoObject extends PDO {
 
     public function select(string $sql, array $parameters = []): PDOStatement {
+        # var_dump($sql, $parameters); die();
+        
         try {
             if (false !== ( $statement = $this->prepare($sql) )) {
                 $statement = $this->execute($statement, $parameters, false);
@@ -21,6 +23,8 @@ class PdoObject extends PDO {
     }
 
     public function runQuery(string $sql, array $parameters = []): ? PDOStatement {
+       # dump($sql, $parameters); return null;
+        
         try {
             if (false !== ( $statement = $this->prepare($sql) )) {
                 return $this->execute($statement, $parameters, true);
diff --git a/src/EntityCollection.php b/src/EntityCollection.php
index 5c3ffe0..031a190 100644
--- a/src/EntityCollection.php
+++ b/src/EntityCollection.php
@@ -30,12 +30,14 @@ class EntityCollection extends \ArrayObject {
         return $collection;
     }
     
-    public function searchOne($value, string $field) : object 
+    public function searchOne($value, string $field) : ? object 
     {
         # Returning first value only
         foreach($this->search($value, $field) as $item) {
             return $item;
         }
+        
+        return null;
     }
     
     public function search($value, string $field) : Generator 
diff --git a/src/Repository.php b/src/Repository.php
index cca915f..d5c8c2b 100644
--- a/src/Repository.php
+++ b/src/Repository.php
@@ -105,9 +105,7 @@ class Repository
                 throw new \Exception(sprintf("No primary key found for entity %s", $this->entityClass));
             }
 
-            $diff = array_diff_assoc($dataset, $entity->entityGetDataset(true));
-            
-            if ( [] !== $diff ) {
+            if ( [] !== $diff = $this->generateDatasetDiff($entity) ) {
                 $pkField = key($primaryKeyDefinition);
                 $pkFieldName = $primaryKeyDefinition[$pkField]->name ?? $pkField;
                 $this->where($pkFieldName, $dataset[$pkFieldName]);
@@ -128,6 +126,11 @@ class Repository
         }
     }
     
+    public function generateDatasetDiff(object $entity) : array
+    {
+        return array_diff_assoc( array_change_key_case($entity->toArray()), array_change_key_case($entity->entityGetDataset(true)) );
+    }
+    
     public function yieldAll() : \Generator
     {