Database Error of CI on my online server HELP!!!!!

[eluser]Xeroxeen[/eluser]
Hi,

I previously also posted this issue here.But someone told my username and password of the database can be incorrect.So i checked carfully it.Those are correct.But when i’m trying to access the site it’s showing,

Code:

A Database Error Occurred

Unable to connect to your database server using the provided settings.

Filename: core/Loader.php

Line Number: 346

After that now i'm getting this error

Code:

Unable to locate the model you have specified: testmodel

Then i searched all over the internet for a solution.I saw many people have got this issue.But most of them were due to the wrong MySQL credentials in config file.But i’m 100% sure those are correct.Then i saw someone has told to change the debug attribute to FALSE.I did that too.And then chnage mysql to mysqli.It’s also not working.I gave the all privileges to the database user too.So i’m stuck at this point.Please help me CI experts…..