title: How To Interpret This Diagram
body: <p>I am in a database course this semester and I'm trying to figure out how to interpret this diagram
  <a href="https://i.stack.imgur.com/EwmUq.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/EwmUq.png" alt="enter image description here" /></a></p>
  <p>I know the key symbols represent either a primary or foreign key, but I can't tell which ones are which.  I think the tables that have the 2 perpendicular lines have at least one foreign key from the table where the line came from, but I am not 100% sure.  That's about all I (think) I understand.</p>
  <p>What I really need is someone to either tell me the name of this type of diagram and/or how to interpret it so that I can write the SQL script to represent it.</p>