mysql - 自动更新另一个表中的事件

I have two tables, one for storing reports of a user, and another for storing users.

1. Report_table
-----report_id(P)-----user_id--------
        001           user1
        002           user1 
        003           user3


2.Users table 
-------user_id(P)-------no_of_reports
        user1             2
        user2             0
        user3             1 

现在，每当在 report_table 中插入报告时(比如 report_id:004，user_id:user1)，我都会像这样更新两个表.

INSERT INTO reports_table VALUES (004,`user1`)
INSERT INTO users_table  (user_id,no_of_reports) VALUES (`user1`,1)
  ON DUPLICATE KEY UPDATE no_of_reports=no_of_reports+1;