Thank you dekzgimutao
Yes, it did a perfect job when both of your database are at the same server (I guess from your comment up there, sorry if I misunderstand about that), I also test that plugin on my local PC and it works too. After that I did some more searches and I’m quite sure that this plugin will not function properly when two databases are located at different hosts. (Please let me know if I get this wrong)
Anyway I solve this problem by moving my WordPress to cloud system and Boom! This plug-in save the day 🙂
