How to fetch data from database by parameter?

Question

PHP

There are 2 databases in the structure, it should be implemented like this:
I enter a certain value, for example, the id of a product, and it gives me information from another database.
I thought it was necessary like this: 'SELECT * FROM `table_products` WHERE 'id_product' = {$id}'
But it doesn't work, tell me! Thank you!

Answer 1

Are you sure you mean 2 DIFFERENT DATABASES and not 2 different tables?
In the general case, for two different databases, you need to create 2 different connections and make sequentially first one request to one database, then the second - to the second.
If you meant 2 different tables, then here is some food for thought (JOIN) .
You need to use the JOIN statement to join one table to another based on some criteria, usually using FOREIGN KEYs.