每当学生的受欢迎程度更新并成为<50,该学生应从"x"小组中除名。
UPDATE student
SET popularity = 52
WHERE id = 2;
结果:没有这样的列:受欢迎程度
错误在哪里?
您想要对NEW
的引用。所以我认为逻辑是:
CREATE TRIGGER t1
AFTER UPDATE ON student
FOR EACH ROW
when new.popularity < 50
begin
delete from ismember
where new.id = ismember.sid and team = 'cool_guys';
end;