I am creating custom attributes and magento 2.2.6 and I just want the list of the tables effected after an order creates successfully.
sales_order the main order entity table
sales_order_item contains the order items (one entry or two entries for each order line, two for example for configurable products)
sales_order_address contains the addresses of an order (one entry for billing and one for shipping)
sales_order_payment contains payment realated data
sales_order_grid contains data which is used in the grid view in backend
sales_order_tax_item contains tax information about applied tax rates
There are some more involved tables like
quote or the customer tables where data is updated depending on what happens in the order (e.g. a customer registres during checkout)
There are also some more tables implied for invoice creation (depending on your payment an invoice may be created directly) or credit memos.