Types of Join(1/4)

Question

Task:
"Fill in the blanks to select item names and names of customers who bought the items. Use custom names to shorten the statement."

code:
SELECT ct.name, it.name ...
... WHERE it.seller_id= .id;

My question:
Where does seller_id come from?
Shouldn't there be it.customer_id instead?
update:
the same goes for: Types of Join 3/4
looks like some kind of common practice to give a column of customers ids in the items table the name of seller_id
or is this the same mistake again?

Answer 1

Sololearn has a habit of misleading learners with how they present material. Seller_id comes from the items table, where customer_id is the identity of the person who bought it.

Answer 2

full (union)
left
right
inner