update

app/Http/Controllers/Admin/CourseContentController.php

@@ -82,7 +82,7 @@ class CourseContentController extends BaseController
                         }
                         // null搜索
                         if ($op == 'null') {
-                            $query->whereNull($key)->where('json_length(' . $key . ') =', 0);
+                            $query->whereNull($key)->orWhere('json_length(' . $key . ') =', 0);
                         }
                         // notnull搜索
                         if ($op == 'notnull') {