Database Import for Staging

We are just trying to import live database to our staging server to solve this issue at our demo server first.
Without this I can not check the issue because we may need to alter and optimize some database quiries , and we can not perform his on live site directly
Correct above sentence

Here's a revised version of your sentence:

"We are trying to import the live database to our staging server to address the issue on our demo server first. Without this, I cannot check the issue because we may need to alter and optimize some database queries, and we cannot perform this directly on the live site."