MyBatis Oracle begin...end block

I need say sorry, firstly. I am in china, and i cant get stackoverflow.com. my network is not allow me do that. the question is followed. when i use mybatis with Oracle begin-end block. i want to execute two update once. this is my code:

    @Update("begin" +
            " update pt_jg set usernum = usernum+1 where jgbh in (#{bm});" +
            " update pt_bm set usernum = usernum+1 where bmbh in (#{bm});" +
            "end;")
    public int incUsernum(@Param("bm") String bm);

its no warnings or errors. but it does not work. the database has no changes. the oracle version is 12c. thankyou for you guys.