I have designed a SQL Server 2008R2 database, and have created a diagram. I am wondering whether creating relationships (drag-drop) between my tables in this diagram affects the tables and queries in any way, or is it just for visual purposes?
I know, this seems like a silly question, but I've discovered that I have still a whole lot to learn about designing databases, so your help will be appreciated, thanks.
Also, what is the difference between having the child as foreign key in the parent table, and the parent as foreign key in the child table, and also what effect does having both situations? Is there a standard for this?