Mysql 我对这个sql触发器有问题

我正在写一个触发器，当新员工被雇佣时，它会在工资表中设置50000的新员工工资。到目前为止，我启动了触发器，但不知道如何进行IF语句。如果您能帮忙，我们将不胜感激

EMPLOYEE:
    +-----------+----------+------+-----+---------+-------+
    | Field     | Type     | Null | Key | Default | Extra |
    +-----------+----------+------+-----+---------+-------+
    | staff_id  | int(11)  | NO   |PRI  | NULL    |       | 
    | seniority | int(11)  | YES  |     | NULL    |       | 
    | lastname  | char(30) | YES  |     | NULL    |       | 
    | firstname | char(30) | YES  |     | NULL    |       |
    +-----------+----------+------+-----+---------+-------+

SALARY:
+-----------+----------+------+-----+---------+-------+
| Field     | Type     | Null | Key | Default | Extra |
+-----------+----------+------+-----+---------+-------+
| staff_id  | int(11)  | NO   |PRI  | NULL    |       | 
| salary    | int(16)  | YES  |     | NULL    |       | 
+-----------+----------+------+-----+---------+-------+
delimiter $$

Create Trigger Salary_add
   BEFORE INSERT ON employee
   FOR EACH ROW
BEGIN
   DECLARE num_row INTEGER;
   DECLARE tot_rows INTEGER;

SELECT COUNT(*)
   INTO tot_rows
   FROM employee
   WHERE staff_id=NEW.staff_id;

SELECT COUNT(*)
   INTO num_row
   FROM salary
   WHERE staff_id=NEW.staff_id;

IF num_row > 0 THEN
    UPDATE employee

    WHERE staff_id = NEW.staff_id;

ELSE
INSERT INTO employee
    (staff_id, seniority, lastname, firstname)
    VALUES(NEW.staff_id, NEW.seniority, NEW.lastname, NEW.firstname);
END IF


end$$

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你在找这个吗

创建触发工资\u添加 在插入员工姓名后 每行 在工资值中插入新的员工id，50000；

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这是一个演示

非常感谢您。我所要做的就是将update改为insert。SQLFIDLE是否有日志，比如在mysql cli中的何处可以执行/t日志