Validating Information....error with query...No connection could be made because the target machine actively refused it

I have created php connect with php database. I checked locally its working well. I have moved server Its showing error. changed the database config details. It is showing, but this code connect xampp locally that time working well. I get this error:

Validating Information....error with query: SELECT ID,fname,lname,email,userlevel,user_group,orgID FROM students WHERE username='test' AND password='123456' No connection could be made because the target machine actively refused it.