DELIMITER //
CREATE TRIGGER before_instructor_insert BEFORE INSERT ON instructor 
FOR EACH ROW
BEGIN
    DECLARE dept_count INT;
    SELECT COUNT(dept_name) INTO dept_count FROM department WHERE dept_name = NEW.dept_name;
    IF dept_count <> 1 THEN
        INSERT INTO department VALUES(NEW.dept_name, NULL, NULL);
    END IF; 
END //
DELIMITER ;

INSERT INTO instructor VALUES(9, 'DEF1', 'CIVIL', 900);
---------------------------------------------------------------------------------------------------
DELIMITER //
CREATE TRIGGER after_instructor_insert AFTER INSERT ON instructor 
FOR EACH ROW
BEGIN
    DECLARE dept_count INT;
    SELECT COUNT(dept_name) INTO dept_count FROM department WHERE dept_name = NEW.dept_name;
    IF dept_count <> 1 THEN
         INSERT INTO department VALUES(NEW.dept_name, NULL, NULL);
    END IF; 
END //
DELIMITER ;

INSERT INTO instructor VALUES(10, 'DEF2', 'BIO', 1000);