Trying to export the gradebook as Excel spreadsheet causes SQL errors if an Oracle database is being used.

The issue occurs in two spots: (1) the preview and (2) when a user actually clicks on the download button.

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(1) Preview SQL Error:
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Debug info: ORA-00923: FROM keyword not found where expected
SELECT u.*, cf0.data AS 'customfield_managersemail' , u.lastname AS usrt1, u.firstname AS usrt2, u.id AS usrt
FROM m_user u
JOIN (SELECT DISTINCT eu1_u.id
FROM m_user eu1_u
JOIN m_user_enrolments eu1_ue ON eu1_ue.userid = eu1_u.id
JOIN m_enrol eu1_e ON (eu1_e.id = eu1_ue.enrolid AND eu1_e.courseid = :o_eu1_courseid)
WHERE eu1_u.deleted = 0 AND eu1_u.id <> :o_eu1_guestid AND eu1_ue.status = :o_eu1_active AND eu1_e.status = :o_eu1_enabled AND eu1_ue.timestart < :o_eu1_now1 AND (eu1_ue.timeend = 0 OR eu1_ue.timeend > :o_eu1_now2)) je ON je.id = u.id

LEFT JOIN (SELECT * FROM m_user_info_data
WHERE fieldid = :o_cf0) cf0
ON u.id = cf0.userid
JOIN (
SELECT DISTINCT ra.userid
FROM m_role_assignments ra
WHERE ra.roleid IN (:o_grbr9,:o_grbr10)
AND ra.contextid IN (2265,654,1)
) rainner ON rainner.userid = u.id
WHERE u.deleted = 0

ORDER BY usrt1 ASC, usrt2 ASC, usrt ASC
[array (
'o_eu1_courseid' => '464',
'o_eu1_guestid' => '1',
'o_eu1_active' => 0,
'o_eu1_enabled' => 0,
'o_eu1_now1' => 1378997300,
'o_eu1_now2' => 1378997300,
'o_cf0' => '22',
'o_grbr9' => '5',
'o_grbr10' => '7',
)]
Error code: dmlreadexception
Stack trace:

line 423 of /lib/dml/moodle_database.php: dml_read_exception thrown
line 280 of /lib/dml/oci_native_moodle_database.php: call to moodle_database->query_end()
line 1096 of /lib/dml/oci_native_moodle_database.php: call to oci_native_moodle_database->query_end()
line 216 of /grade/lib.php: call to oci_native_moodle_database->get_recordset_sql()
line 244 of /grade/export/lib.php: call to graded_users_iterator->init()
line 61 of /grade/export/xls/index.php: call to grade_export->display_preview()

---------------------------------------------------------------------
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(2) Download SQL Error:
-----------------------------------------------
Debug info: ORA-00923: FROM keyword not found where expected
SELECT u.*, cf0.data AS 'customfield_managersemail' , u.lastname AS usrt1, u.firstname AS usrt2, u.id AS usrt
FROM m_user u
JOIN (SELECT DISTINCT eu1_u.id
FROM m_user eu1_u
JOIN m_user_enrolments eu1_ue ON eu1_ue.userid = eu1_u.id
JOIN m_enrol eu1_e ON (eu1_e.id = eu1_ue.enrolid AND eu1_e.courseid = :o_eu1_courseid)
WHERE eu1_u.deleted = 0 AND eu1_u.id <> :o_eu1_guestid AND eu1_ue.status = :o_eu1_active AND eu1_e.status = :o_eu1_enabled AND eu1_ue.timestart < :o_eu1_now1 AND (eu1_ue.timeend = 0 OR eu1_ue.timeend > :o_eu1_now2)) je ON je.id = u.id

LEFT JOIN (SELECT * FROM m_user_info_data
WHERE fieldid = :o_cf0) cf0
ON u.id = cf0.userid
JOIN (
SELECT DISTINCT ra.userid
FROM m_role_assignments ra
WHERE ra.roleid IN (:o_grbr1,:o_grbr2)
AND ra.contextid IN (2265,654,1)
) rainner ON rainner.userid = u.id
WHERE u.deleted = 0

ORDER BY usrt1 ASC, usrt2 ASC, usrt ASC
[array (
'o_eu1_courseid' => '464',
'o_eu1_guestid' => '1',
'o_eu1_active' => 0,
'o_eu1_enabled' => 0,
'o_eu1_now1' => 1378997600,
'o_eu1_now2' => 1378997600,
'o_cf0' => '22',
'o_grbr1' => '5',
'o_grbr2' => '7',
)]
Error code: dmlreadexception
Stack trace:

line 423 of /lib/dml/moodle_database.php: dml_read_exception thrown
line 280 of /lib/dml/oci_native_moodle_database.php: call to moodle_database->query_end()
line 1096 of /lib/dml/oci_native_moodle_database.php: call to oci_native_moodle_database->query_end()
line 216 of /grade/lib.php: call to oci_native_moodle_database->get_recordset_sql()
line 69 of /grade/export/xls/grade_export_xls.php: call to graded_users_iterator->init()
line 49 of /grade/export/xls/export.php: call to grade_export_xls->print_grades()