/**
* SQL to fetch relevant 'quiz_attempts' records.
*
* @param int $quizid quiz id to get attempts for
* @param array $groupstudents empty array if not using groups or array of students in current group.
* @param string $whichattempts which attempts to use, represented internally as one of the constants as used in
* $quiz->grademethod ie.
* QUIZ_GRADEAVERAGE, QUIZ_GRADEHIGHEST, QUIZ_ATTEMPTLAST or QUIZ_ATTEMPTFIRST
* we calculate stats based on which attempts would affect the grade for each student.
* @param bool $includeungraded whether to fetch ungraded attempts too
* @return array FROM and WHERE sql fragments and sql params
*/
function quiz_statistics_attempts_sql($quizid, $groupstudents, $whichattempts = QUIZ_GRADEAVERAGE, $includeungraded = false)
{
global $DB;
$fromqa = '{quiz_attempts} quiza ';
$whereqa = 'quiza.quiz = :quizid AND quiza.preview = 0 AND quiza.state = :quizstatefinished';
$qaparams = array('quizid' => (int) $quizid, 'quizstatefinished' => quiz_attempt::FINISHED);
if ($groupstudents) {
ksort($groupstudents);
list($grpsql, $grpparams) = $DB->get_in_or_equal(array_keys($groupstudents), SQL_PARAMS_NAMED, 'statsuser');
list($grpsql, $grpparams) = quiz_statistics_renumber_placeholders($grpsql, $grpparams, 'statsuser');
$whereqa .= " AND quiza.userid {$grpsql}";
$qaparams += $grpparams;
}
$whichattemptsql = quiz_report_grade_method_sql($whichattempts);
if ($whichattemptsql) {
$whereqa .= ' AND ' . $whichattemptsql;
}
if (!$includeungraded) {
$whereqa .= ' AND quiza.sumgrades IS NOT NULL';
}
return array($fromqa, $whereqa, $qaparams);
}
public function test_quiz_statistics_renumber_placeholders_work_to_do()
{
list($sql, $params) = quiz_statistics_renumber_placeholders('frog1 IN (:frog100 , :frog101)', array('frog100' => 1, 'frog101' => 2), 'frog');
$this->assertEquals('frog1 IN (:frog1 , :frog2)', $sql);
$this->assertEquals(array('frog1' => 1, 'frog2' => 2), $params);
}
