From a2ed62b3c4fca65dc87888ea835e1d33aadbf75c Mon Sep 17 00:00:00 2001
From: Seamus Lee <seamuslee001@gmail.com>
Date: Wed, 8 Nov 2017 08:09:50 +1100
Subject: [PATCH] CRM-21363 Only implement ONLY_FULL_GROUP_BY if it is in the
 default global sql_modes

---
 CRM/Core/DAO.php  |  2 +-
 CRM/Utils/SQL.php | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/CRM/Core/DAO.php b/CRM/Core/DAO.php
index 1077d8cbe0..503a896e76 100644
--- a/CRM/Core/DAO.php
+++ b/CRM/Core/DAO.php
@@ -120,7 +120,7 @@ class CRM_Core_DAO extends DB_DataObject {
     CRM_Core_DAO::setFactory($factory);
     $currentModes = CRM_Utils_SQL::getSqlModes();
     if (CRM_Utils_Constant::value('CIVICRM_MYSQL_STRICT', CRM_Utils_System::isDevelopment())) {
-      if (CRM_Utils_SQL::supportsFullGroupBy() && !in_array('ONLY_FULL_GROUP_BY', $currentModes)) {
+      if (CRM_Utils_SQL::supportsFullGroupBy() && !in_array('ONLY_FULL_GROUP_BY', $currentModes) && CRM_Utils_SQL::isGroupByModeInDefault()) {
         $currentModes[] = 'ONLY_FULL_GROUP_BY';
       }
       if (!in_array('STRICT_TRANS_TABLES', $currentModes)) {
diff --git a/CRM/Utils/SQL.php b/CRM/Utils/SQL.php
index 1e8897f802..fb4c41273b 100644
--- a/CRM/Utils/SQL.php
+++ b/CRM/Utils/SQL.php
@@ -96,4 +96,19 @@ class CRM_Utils_SQL {
     return FALSE;
   }
 
+  /**
+   * CHeck if ONLY_FULL_GROUP_BY is in the global sql_modes
+   * @return bool
+   */
+  public static function isGroupByModeInDefault() {
+    if (!self::supportsFullGroupBy()) {
+      return FALSE;
+    }
+    $sqlModes = explode(',', CRM_Core_DAO::singleValueQuery('SELECT @@global.sql_mode'));
+    if (!in_array('ONLY_FULL_GROUP_BY', $sqlModes)) {
+      return FALSE;
+    }
+    return TRUE;
+  }
+
 }
-- 
2.25.1