Errors after upgrading magento 2.1.8 to 2.2.2

[mytekdigital]

Hi! I was upgrading my magento store from 2.1.8 to 2.2.2.

Now when I am trying to go to the store it says 404 not found.

What's worst when i am doing: bin/magento setup:upgrade I've got:

Installing schema... SQLSTATE[42S02]: Base table or view not found: 1146 Table 'mjurewic_us.sales_order_grid' doesn't exist, query was: DESCRIBE `sales_order_grid`

And there is no sales_order_grid in database

What can i do?

[Darren Grant]

If you are using nginx as web server, the first problem I found is the update removed the nginx.conf.sample file, if that is included in your nginx configuration then everything will come up as 404. The .php files also disappeared from the pub directory, the main one being index.php !

I dispair every time a magento update comes out as it rarely goes to plan.