Suppose I’ve the next relationship diagram:
How would you describe the connection decided by the pink line?
Studying from left to proper you’ll say every order has just one buyer so it might be described as a “many to 1” whereas from proper to left every buyer can have many orders so you could possibly say it’s “one to many”.
With out path it appears to me to be futile to attempt to talk about a relationship but I not often see folks say, it’s a one to many (from buyer to order) or many to 1 (from order to buyer).
So my query is why is that this the case (is it simply implied from context?) or does the first key have some relation, as in we would not actually retailer an order_ID within the buyer desk (I’m not a DBA however I do not assume this make sense from a design perspective) whereas we must retailer a buyer as a international key within the order desk in any other case we would not know who purchased the stuff, so would this give priority to studying from proper to left and we are saying the pink line is a one to many relationship?
Any clarification could be nice!