Kindly reported by Onno here: https://moodle.org/mod/forum/discuss.php?d=448092

The code:

ON {c.id} = e.courseid 

should be:

ON c.id = e.courseid 

Note: This SQL will be in the sync_tool_grades task in 4.2 and newer. In 4.1, it'll be in the main sync_grades task.

This only impacts the case where we're creating the grade item for a published course having a decoupled grade item. I.e. the launch has included an AGS claim, but hasn't included a 'lineitem' endpoint, meaning the tool is free to manage its own line items in the gradebook. This won't impact shared activities, nor any shared items with coupled line items (those which include a 'lineitem' property in the AGS claim).

Replication instructions:

1. Setup two sites using LTI Advantage; one platform, one tool
2. In the tool site, create a course with an assignment in it.
3. Publish the entire course as an LTI tool (course context is important)
4. In the platform site, create the external tool instance such that you're able to launch into the published course (use deep linking)
5. Edit the settings of that activity and set:
   • Privacy > Accept grades from the tool = Yes
   • Grade type: None
     (This results in the ags claim ONLY sending 2 items: the 'scope' property and the 'lineitems' property (importantly, NOT the 'lineitem' property for the specific grade item, since the grade is set to None)
6. Launch
7. Log in to the platform as a student user s1
8. Launch into the tool (we don't need a submission here, just a launch)
9. Log out
10. Log in to the platform as the admin
11. Go to the course
12. Launch the tool and go to the assignment
13. Click "View all submissions"
14. Click the "Quick grading" checkbox
15. Set a grade for the student s1, say '55'
16. Now, in the root of the tool site, run:

php admin/cli/scheduled_task.php --execute="enrol_lti\local\ltiadvantage\task\sync_grades" 

On 4.2+, this will schedule the adhocs that sync grades

1. Then run:

php admin/cli/adhoc_task.php --execute 

This will process the adhoc tasks for grade syncing

1. Inspect the terminal output
   Expected: You see "The grade 'xx' was sent" (xx will be whatever the expected course grade was)
   Actual: You see (ignore the letter placeholders here, yours will be different):

Failed - The grade 'xx' for the user 'yy', for the resource 'zz' and the course 'a' failed to send.

Error reading from database (ERROR:  syntax error at or near "{"

LINE 6:                                   ON {c.id} = e.courseid 

SELECT c.fullname

                                FROM mdl_enrol_lti_tools t

                                JOIN mdl_enrol e

                                  ON (e.id = t.enrolid)

                                JOIN mdl_course c

                                  ON {c.id} = e.courseid

                               WHERE t.id = $1

[array (

  0 => '14',

)])