Merge pull request yajra#2084 from Arkhas/9.0

[9.0] Enable the dotted notation in the ->only() function.

Author: yajra

src/Processors/DataProcessor.php

@@ -180,7 +180,17 @@ protected function selectOnlyNeededColumns(array $data)
         if (is_null($this->onlyColumns)) {
             return $data;
         } else {
-            return array_intersect_key($data, array_flip(array_merge($this->onlyColumns, $this->exceptions)));
+            $results = [];
+            foreach ($this->onlyColumns as $onlyColumn) {
+                Arr::set($results, $onlyColumn, Arr::get($data, $onlyColumn));
+            }
+            foreach ($this->exceptions as $exception) {
+                if ($column = Arr::get($data, $exception)) {
+                    Arr::set($results, $exception, $column);
+                }
+            }
+
+            return $results;
         }
     }