update

app/Models/CourseSign.php

@@ -106,7 +106,7 @@ class CourseSign extends SoftDeletesModel
     /**
      * 指定时间内的报名信息(去重)
      */
-    public static function courseSignsTotalByUnique($start_date, $end_date, $status = null, $course_ids = null, $area = null, &$userIds)
+    public static function courseSignsTotalByUnique($start_date, $end_date, $status = null, $course_ids = null, $area = null, &$userIds = null)
     {
         $courseSignByType = CourseSign::whereDate('created_at', '>=', $start_date)
             ->whereDate('created_at', '<=', $end_date)