PLSQL技巧总结

1.导入数据:

2.SQL执行顺序:

 eg.  select to_char(login_time,'HH24') logintime,count(*) from login_log_p group by to_char(login_time,'HH24') order by logintime;

(1).from login_log_p查表
(2).group by to_char(login_time,'HH24')分组
(3).select to_char(login_time,'HH24') logintime,count(*) 选择选项
(4).order by logintime 排序