Merge pull request #65 from lucknessbuaa/master

add the choice time of the recommend message
更改时间为时间戳格式
Merge pull request #66 from hexiaoming/master

更改时间为时间戳格式
增加排序功能
Merge pull request #67 from hexiaoming/master

增加排序功能
增加降序排列
Merge pull request #68 from hexiaoming/master

增加降序排列
insert data into database