I have a general doubt in MySql foreign key constraints and Magento.
As per MySql, a table should have only one primary key for a table and a Primary key should contain unique values.
I checked in "cms_block_store" and "cms_page_store" Magento tables. In that, both table block_id, page_id, and store_id columns are declared as foreign keys and at the same time mentioned as primary keys.
Here two primary keys declared in a table and A foreign key cannot contain unique values but at the same time A primary key should contain unique values, but here the fields are working with the duplicate entries even the fields are mentioned as Primary keys.
Please check the attached screenshots:
"cms_block_store" table structure:
"cms_page_store" table structure:
Can someone help me to understand how working in Magento against MySql?