title: understanding arrow tips in MySQL Workbench EER diagram
body: <p>I used the reverse-engineer function to generate an EER diagram of the Yelp dataset as per this question <a href="https://stackoverflow.com/questions/2488/auto-generate-database-diagram-mysql">here</a>. It looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/oU13w.png" rel="noreferrer"><img src="https://i.stack.imgur.com/oU13w.png" alt="EER diagram yelp dataset"></a></p>
  
  <p>Does anyone know exactly how to interpret it? What do the arrow tips mean, eg the one with 3 tips and a line, the one with 2 parallel lines. Then there are some without any tips.</p>
  
  <p>Then, does the point at which the arrow enter or leave a table mean anything, eg one leaves the tip table around text and enters the checkin table around count, or is that irrelevant?</p>
  
  <p>Another detail I noticed in there is that the yellow lightbulb is probably a primary key and the red diamond, a foreign key. Still can't see from the diagram however how the coloured symbols and arrows connect.</p>