From df986a59fcab2edd5d6d1c396dad9b79f7e52db9 Mon Sep 17 00:00:00 2001
From: Adrian Greeve <adrian@moodle.com>
Date: Fri, 11 May 2018 10:02:34 +0800
Subject: [PATCH] MDL-61814 report_stats: Update to sql to increase
 performance.

---
 report/stats/classes/privacy/provider.php | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/report/stats/classes/privacy/provider.php b/report/stats/classes/privacy/provider.php
index 7dc8b837f6a..5db4f4f8bb1 100644
--- a/report/stats/classes/privacy/provider.php
+++ b/report/stats/classes/privacy/provider.php
@@ -87,16 +87,27 @@ class provider implements \core_privacy\local\metadata\provider, \core_privacy\l
      * @return  contextlist $contextlist The contextlist containing the list of contexts used in this plugin.
      */
     public static function get_contexts_for_userid(int $userid) : contextlist {
-        $params = ['dailyuser' => $userid, 'weeklyuser' => $userid, 'monthlyuser' => $userid, 'contextcourse' => CONTEXT_COURSE];
+        $params = ['userid' => $userid, 'contextcourse' => CONTEXT_COURSE];
         $sql = "SELECT ctx.id
                 FROM {context} ctx
-                LEFT JOIN {stats_user_daily} sud ON sud.courseid = ctx.instanceid
-                LEFT JOIN {stats_user_weekly} suw ON suw.courseid = ctx.instanceid
-                LEFT JOIN {stats_user_monthly} sum ON sum.courseid = ctx.instanceid
-                WHERE ctx.contextlevel = :contextcourse
-                AND (sud.userid = :dailyuser OR suw.userid = :weeklyuser OR sum.userid = :monthlyuser)";
+                JOIN {stats_user_daily} sud ON sud.courseid = ctx.instanceid AND sud.userid = :userid
+                WHERE ctx.contextlevel = :contextcourse";
+
         $contextlist = new contextlist();
         $contextlist->add_from_sql($sql, $params);
+
+        $sql = "SELECT ctx.id
+                FROM {context} ctx
+                JOIN {stats_user_weekly} suw ON suw.courseid = ctx.instanceid AND suw.userid = :userid
+                WHERE ctx.contextlevel = :contextcourse";
+        $contextlist->add_from_sql($sql, $params);
+
+        $sql = "SELECT ctx.id
+                FROM {context} ctx
+                JOIN {stats_user_monthly} sum ON sum.courseid = ctx.instanceid AND sum.userid = :userid
+                WHERE ctx.contextlevel = :contextcourse";
+        $contextlist->add_from_sql($sql, $params);
+
         return $contextlist;
     }