[-] Installer : fixed errors at the installation with insertion of null values in the database #PSCFV-3544

classes/ObjectModel.php

@@ -270,7 +270,7 @@ abstract class ObjectModelCore
 			$fields = array_merge($fields, $this->getFieldsShop());
 
 		// Ensure that we get something to insert
-		if (!$fields)
+		if (!$fields && $this->id)
 			$fields[$this->def['primary']] = $this->id;
 		return $fields;
 	}
@@ -286,7 +286,7 @@ abstract class ObjectModelCore
 	public function getFieldsShop()
 	{
 		$fields = $this->formatFields(self::FORMAT_SHOP);
-		if (!$fields)
+		if (!$fields && $this->id)
 			$fields[$this->def['primary']] = $this->id;
 		return $fields;
 	}

classes/db/Db.php

@@ -322,7 +322,7 @@ abstract class DbCore
 	 */
 	public function insert($table, $data, $null_values = false, $use_cache = true, $type = Db::INSERT, $add_prefix = true)
 	{
-		if (!$data)
+		if (!$data && !$null_values)
 			return true;
 
 		if ($add_prefix)