Check if inserted row is the same as current

Question

I have a table named ticket. I get the data of all tickets from another base and put it in mine with simple Insert.

By clicking a button on my website, I want the user to be able to update the tickets. Basically I would like to do all these points without making too much code :

• The new tickets that are not already in my base will be inserted
• The tickets already inserted which data is not up to date will be updated
• The tickets already inserted which data is up to date will be ignored

By now, I've tried to make a trigger which looks like this:

CREATE TRIGGER before_insert_task BEFORE INSERT
ON ticket FOR EACH ROW
BEGIN
    UPDATE ticket
    SET technician = NEW.technician,
    date = NEW.date,
    closeDate = NEW.closeDate,
    solution = NEW.solution,
    content = NEW.content,
    actiontime = NEW.actiontime;
END

This does not work, I saw that you cant make trigger that update before/after insert.