MySQL触发器插入之前

Question

I'm trying to write a trigger that will insert a default value in another table

After inserting a Record into my Students Table I want to insert a new record into my Student_Chapter Table.

The Student Table has field called S_ID which is auto incremented and the Primary Key for that table.

The Student_Chapter table has two fields Student_ID Int Chapter_ID Int

I tried to create this trigger to fire when you enter a new Student Record. However I get an error trying to create it...and I've tried several things...and looks at various examples on this site.

Create Trigger AssignDefaultChapter_trigger 
Before INSERT On Students
FOR EACH ROW
BEGIN
    DECLARE Default_ID INT;
        SET Default_ID =(SELECT C_ID FROM Chapter WHERE ChName = "UNASSIGNED";
    Insert into Student_Chapter(Chapter_ID,Student_ID) values (Default_ID,New.S_ID);
END;

As far as I can see there is nothing wrong with that insert.

The Error I get is #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 '; Insert into Student_Chapter (Chapter_ID, Student_ID) values (Default_ID,NEW.' at line 6

Answer 1

A missing ) ? after the "UNASSIGNED" Also, shouldnt you prefix your parameters with a @

Create Trigger AssignDefaultChapter_trigger 
Before INSERT On Students
FOR EACH ROW
BEGIN
    DECLARE @Default_ID INT;
        SELECT @Default_ID = C_ID FROM Chapter WHERE ChName = "UNASSIGNED";
    Insert into Student_Chapter(Chapter_ID,Student_ID) values (@Default_ID,New.S_ID);
END;