MySQL workbench error 1064 when adding trigger - mysql

Question

I am new to SQL and more specifically using MySQL Workbench.
I have created a database with two tables Grades and GPAList.
I want to take the average value of every entry in Grades (grouped by student id [sid is the name of the column]) once I have those averages, store them in the GPAList table with their corresponding students. This is intended to trigger every time a new entry is added to Grades.
This is the trigger that I have created:
CREATE DEFINER = CURRENT_USER TRIGGER `ProjectName`.`Grades_AFTER_UPDATE_1` AFTER UPDATE ON `Grades` FOR EACH ROW
BEGIN
SELECT sid, SUM ( CASE grade
when 'A' then 4.0
when 'B' then 3.5
when 'C' then 3.0
when 'D' then 2.5
when 'F' then 1.0
else 0
end
) / COUNT(*) Grades
INTO GPAList
FROM Grades
GROUP BY sid;
END
The error that I am encountering is:
Error 1064: You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use near '' at
line 1 SQL Statement: CREATE DEFINER = CURRENT_USER TRIGGER
`ProjectName`.`Grades_AFTER_UPDATE_1` AFTER UPDATE ON `Grades` FOR EACH ROW
FOLLOWS `Grades_AFTER_UPDATE`
When I write this code in the workbench, no syntax errors are shown. When I try to apply this trigger, my code is converted to:
DROP TRIGGER IF EXISTS `ProjectName`.`Grades_AFTER_UPDATE_1`;
DELIMITER $$
USE `ProjectName`$$
CREATE DEFINER = CURRENT_USER TRIGGER `ProjectName`.`Grades_AFTER_UPDATE_1` AFTER UPDATE ON `Grades` FOR EACH ROW FOLLOWS `Grades_AFTER_UPDATE`
$$
DELIMITER ;
Only after clicking apply once more do I see the 1064 error listed above. Is there some easy fix that I am missing?
There is a Grades_AFTER_UPDATE that Grades_AFTER_UPDATE_1 is following, so that shouldn't be the problem.

Answer 1

I'm not sure why you would want to store all averages after a single insert, but the correct insert logic is something like this:
INSERT INTO GPALIST(sid, grades)
SELECT sid,
AVG (CASE grade
when 'A' then 4.0
when 'B' then 3.5
when 'C' then 3.0
when 'D' then 2.5
when 'F' then 1.0
else 0
end) as Grades
FROM Grades
GROUP BY sid;
I suspect the trigger would want to access new. somewhere along the way.