Some time I am Unable to connect to my database server
I am running a PHP application with mySQL . Some times it gives the following error.

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

I do not understand why this error occurred .

today I am using the application but it is not giving the error but error occurs yesterday .

please help me . 
Some time I am Unable to connect to my database server
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I am running a PHP application with mySQL . Some times it gives the following error.

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

I do not understand why this error occurred .

today I am using the application but it is not giving the error but error occurs yesterday .

please help me . 