From fb0814ac14759774ba025051b05f07ba9875ccd8 Mon Sep 17 00:00:00 2001
From: Dan Marsden <dan@danmarsden.com>
Date: Mon, 26 Mar 2012 11:20:34 +1300
Subject: [PATCH] MDL-27368 Clean up invalid course completion records keep
 oldest timestamps from all records

---
 lib/db/upgrade.php | 38 ++++++++++++++++++++++++++++++++++++++
 version.php        |  2 +-
 2 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/lib/db/upgrade.php b/lib/db/upgrade.php
index 2b7b6503464..774fe5abdec 100644
--- a/lib/db/upgrade.php
+++ b/lib/db/upgrade.php
@@ -6782,5 +6782,43 @@ FROM
         upgrade_main_savepoint(true, 2011070105.08);
     }
 
+    if ($oldversion < 2011070106.03) { // fix invalid course_completion_records MDL-27368
+        //first get all instances of duplicate records
+        $sql = 'SELECT userid, course FROM {course_completions} WHERE (deleted IS NULL OR deleted <> 1) GROUP BY userid, course HAVING (count(id) > 1)';
+        $duplicates = $DB->get_recordset_sql($sql, array());
+
+        foreach ($duplicates as $duplicate) {
+            $pointer = 0;
+            //now get all the records for this user/course
+            $sql = 'userid = ? AND course = ? AND (deleted IS NULL OR deleted <> 1)';
+            $completions = $DB->get_records_select('course_completions', $sql,
+                array($duplicate->userid, $duplicate->course), 'timecompleted DESC, timestarted DESC');
+            $needsupdate = false;
+            $origcompletion = null;
+            foreach ($completions as $completion) {
+                $pointer++;
+                if ($pointer === 1) { //keep 1st record but delete all others.
+                    $origcompletion = $completion;
+                } else {
+                    //we need to keep the "oldest" of all these fields as the valid completion record.
+                    $fieldstocheck = array('timecompleted', 'timestarted', 'timeenrolled');
+                    foreach ($fieldstocheck as $f) {
+                        if ($origcompletion->$f > $completion->$f) {
+                            $origcompletion->$f = $completion->$f;
+                            $needsupdate = true;
+                        }
+                    }
+                    $DB->delete_records('course_completions', array('id'=>$completion->id));
+                }
+            }
+            if ($needsupdate) {
+                $DB->update_record('course_completions', $origcompletion);
+            }
+        }
+
+        // Main savepoint reached
+        upgrade_main_savepoint(true,2011070106.03);
+    }
+
     return true;
 }
diff --git a/version.php b/version.php
index 32be518e8fa..820fc9597a0 100644
--- a/version.php
+++ b/version.php
@@ -30,7 +30,7 @@
 defined('MOODLE_INTERNAL') || die();
 
 
-$version  = 2011070106.02;              // 20110701      = branching date YYYYMMDD - do not modify!
+$version  = 2011070106.03;              // 20110701      = branching date YYYYMMDD - do not modify!
                                         //         RR    = release increments - 00 in DEV branches
                                         //           .XX = incremental changes