Hi

can someone explain me why it works like this?

=> select client_id from clients_to_delete; ERROR: column "client_id" does not exist at character 8

but, when putting this inside an IN()...

=> select * from orders where client_id in(select client_id from clients_to_delete);

it works! and select all rows in the orders table. Same when running delete/update. Why it doesn't produce an error like before?

Thank you!