PHP MySQL UPDATE查询无效

I am a new PHP coder and I started a project of cms panel with, for start, three options: new article, delete article and edit article. There isn't even one error in my project but, when im trying to edit a post, everything is going well, except the save. The post isn't saved!!! and there aren't any errors! I am trying to fix that problem from yesterday. That's annoying.I am a new PHP coder and I started a project of