From a49d6344407db965af454c7febd8f67acc0b8dda Mon Sep 17 00:00:00 2001
From: Jamie McClelland <jm@mayfirst.org>
Date: Thu, 10 Sep 2015 08:38:48 -0400
Subject: [PATCH] CRM-17191 - ensure Participant list report works with custom
 Grouping

Previously, we got a trace back if a user defined a group by clause.
I've removed what appears to be crufty code that tries to add the
group by fields to an ORDER BY statement - which conflicts with the
existing ORDER BY statement and seems unnecessary. Also, if the user
wants to group by another field, we should not group by the participant
id.
---
 .../Form/Event/ParticipantListCount.php       | 28 +++++--------------
 1 file changed, 7 insertions(+), 21 deletions(-)

diff --git a/CRM/Report/Form/Event/ParticipantListCount.php b/CRM/Report/Form/Event/ParticipantListCount.php
index dfd83d9aad..98fc91d949 100644
--- a/CRM/Report/Form/Event/ParticipantListCount.php
+++ b/CRM/Report/Form/Event/ParticipantListCount.php
@@ -465,29 +465,15 @@ class CRM_Report_Form_Event_ParticipantListCount extends CRM_Report_Form_Event {
     $this->_whereClauses[] = "{$this->_aliases['civicrm_participant']}.is_test = 0";
   }
 
+  // We override this function because we use GROUP functions in the 
+  // SELECT clause, therefore we have to group by *something*. If the
+  // user doesn't select a column to group by, we should group by 
+  // participant id.
   public function groupBy() {
-    $this->_groupBy = "";
-    if (!empty($this->_params['group_bys']) &&
-      is_array($this->_params['group_bys']) &&
-      !empty($this->_params['group_bys'])
-    ) {
-      foreach ($this->_columns as $tableName => $table) {
-        if (array_key_exists('group_bys', $table)) {
-          foreach ($table['group_bys'] as $fieldName => $field) {
-            if (!empty($this->_params['group_bys'][$fieldName])) {
-              $this->_groupBy[] = $field['dbAlias'];
-            }
-          }
-        }
-      }
-    }
-
-    if (!empty($this->_groupBy)) {
-      $this->_groupBy = "ORDER BY " . implode(', ', $this->_groupBy) .
-        ", {$this->_aliases['civicrm_contact']}.sort_name";
+    parent::groupBy();
+    if(empty($this->_groupBy)) {
+      $this->_groupBy = "GROUP BY {$this->_aliases['civicrm_participant']}.id";
     }
-    $this->_groupBy = "GROUP BY {$this->_aliases['civicrm_participant']}.id " .
-      $this->_groupBy;
   }
 
   public function postProcess() {
-- 
2.25.1