From de66ddea5fbd080eb2fcefd4cafdcc5354df9953 Mon Sep 17 00:00:00 2001
From: Adrian Greeve <adrian@moodle.com>
Date: Tue, 15 Sep 2015 13:50:03 +0800
Subject: [PATCH] MDL-51241 cohorts: Update to cohort query.
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This improves the speed of returning a list of
cohorts. Thanks to François Gannaz for providing
this patch.
---
cohort/lib.php | 29 +++++++++++++++++++----------
1 file changed, 19 insertions(+), 10 deletions(-)
diff --git a/cohort/lib.php b/cohort/lib.php
index e859cacb0b6..5c515782c88 100644
--- a/cohort/lib.php
+++ b/cohort/lib.php
@@ -256,15 +256,17 @@ function cohort_get_available_cohorts($currentcontext, $withmembers = 0, $offset
$groupbysql = '';
$havingsql = '';
if ($withmembers) {
- $groupbysql = " GROUP BY $fieldssql";
+ $fieldssql .= ', s.memberscnt';
+ $subfields = "c.id, COUNT(DISTINCT cm.userid) AS memberscnt";
+ $groupbysql = " GROUP BY c.id";
$fromsql = " LEFT JOIN {cohort_members} cm ON cm.cohortid = c.id ";
- $fieldssql .= ', COUNT(DISTINCT cm.userid) AS memberscnt';
if (in_array($withmembers,
array(COHORT_COUNT_ENROLLED_MEMBERS, COHORT_WITH_ENROLLED_MEMBERS_ONLY, COHORT_WITH_NOTENROLLED_MEMBERS_ONLY))) {
list($esql, $params2) = get_enrolled_sql($currentcontext);
$fromsql .= " LEFT JOIN ($esql) u ON u.id = cm.userid ";
$params = array_merge($params2, $params);
- $fieldssql .= ', COUNT(DISTINCT u.id) AS enrolledcnt';
+ $fieldssql .= ', s.enrolledcnt';
+ $subfields .= ', COUNT(DISTINCT u.id) AS enrolledcnt';
}
if ($withmembers == COHORT_WITH_MEMBERS_ONLY) {
$havingsql = " HAVING COUNT(DISTINCT cm.userid) > 0";
@@ -280,13 +282,20 @@ function cohort_get_available_cohorts($currentcontext, $withmembers = 0, $offset
$params = array_merge($params, $searchparams);
}
- $sql = "SELECT $fieldssql
- FROM {cohort} c
- $fromsql
- WHERE $wheresql
- $groupbysql
- $havingsql
- ORDER BY c.name, c.idnumber";
+ if ($withmembers) {
+ $sql = "SELECT " . str_replace('c.', 'cohort.', $fieldssql) . "
+ FROM {cohort} cohort
+ JOIN (SELECT $subfields
+ FROM {cohort} c $fromsql
+ WHERE $wheresql $groupbysql $havingsql
+ ) s ON cohort.id = s.id
+ ORDER BY cohort.name, cohort.idnumber";
+ } else {
+ $sql = "SELECT $fieldssql
+ FROM {cohort} c $fromsql
+ WHERE $wheresql
+ ORDER BY c.name, c.idnumber";
+ }
return $DB->get_records_sql($sql, $params, $offset, $limit);
}