Error establishing a database connection

Just I delete my Wp_options table data than show Error establishing a database connection

– Why did you do that?
– If you have a good backup, restore it
– If you don,t, ask your hosting provider if they do.

I am not sure if I understand your question.

Are you trying to Install a new WordPress on your local host?

Then follow these instructions:
http://codex.wordpress.org/Installing_WordPress#Installing_WordPress_on_your_own_Computer

http://codex.wordpress.org/WordPress_Installation_Techniques#Installing_WordPress_Locally

https://codex.wordpress.org/Installing_WordPress