confusuion aboutdatabase error reason

Respected Forum memebrs

To learn wordpress, i am currently using free hosting on http://www.000webhostapp.com

i was updating themes and clicked on installed themes on my dashboard simultaneously (just after clicking one which took much time to change,so i clicked another theme). Suddenly i found, “error establishing data base connection”.

I did my best for hours, checked my wp-coing.php. everything was correct. DB_host was localhost mention there.

After few hours, i was furstated and edited my DB_Host , and deleted ‘localhost” written there

then reloaded my site, it came back with dashboard also. (after few hours since it was down)

again to confirm my solution, i changed db host name to again localhost. Still my website was running well. didnt found any error.

PS; (after around half and hour of getting error, i deleted all my themes and download one theme which i was using earlier that is sydny and uploded in that theme folder)

I think the problem was with the hosting service provider itself. I dont think i have done any significant changes.

Can u please verify it. What u all think. pl explain , this will help me when i face this issue again in future.

Thanks in Advance. !! ^___^