mysqli :: mysqli（）:( 42000/1044）acess否认

Question

|---------------------------------------
| º www //root folder
| - dbcon.php
| - index.php
   |------------------------------
   |º old_registration  // folder
   |  - old_registration.php  // this one works fine.
   |------------------------------
   |º process    // folder
       |------------------------------
       |º login // folder
       |------------------------------
       |º registration  //folder
       |     - dbcon.php
       |     - registration.php 
       |------------------------------
---------------------------------------

this is what happening.
 the old registration page is working and acessing the mysql database fine.
the new one i made and set the registration page inside 2 folder,  process/registration/. the thing is the everytime it try to acess database it says:

mysqli :: mysqli（）:( 42000/1044）：拒绝用户访问

问题是用户存在，密码是正确的，dbcon.php与旧的注册文件夹和php页面一起正常工作。我想可能是在文件夹内。

尝试使用../../process/registration/dbcon.php和dbcon.php访问dbcon。

在www / dbcon.php里面，它不会成功连接，而www / process / registration / dbcon.php会给我这个错误。

但旧注册是连接和registring帐户。