Prestashop update all prices with SQL (fully working)

I had to update all prices of shop made with PrestaShop. Found some tutorials where in that crazy database prices are saved, but none fully working example in one place. I was updating from prices written in Lithuanian Litas to Euros. 1 Euro = 3.4528 Litas So my solution:

How to join 2 SQL tables with PHP? Examples and visualisations

Often you need to join data from 2 tables. You can do it with several SQL queries and PHP, or just use JOIN functions. The JOIN keyword is used in an SQL statement to query data from two or more tables, based on a relationship between certain columns in these tables. Most popular joins are INNER JOIN, LEFT JOIN, RIGHT JOIN and FULL JOIN. It's always good to know the different.