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understanding arrow tips in MySQL Workbench EER diagram

I used the reverse-engineer function to generate an EER diagram of the Yelp dataset as per this question here. It looks like this:

EER diagram yelp dataset

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.

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?

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.

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cardamom Avatar asked Nov 22 '17 15:11

cardamom


2 Answers

Cardinality and ordinalitiy:

ERD Notation: Cardinality and Ordinality

Source: https://www.lucidchart.com/pages/ER-diagram-symbols-and-meaning

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InfZero Avatar answered Oct 10 '22 08:10

InfZero


In addition to InfZero's answer:

The point at which the connections touch a table figure is random. It's usually the point that produces the shortest connection and is centered on a figure's side. If more than one connection go out on the same side they are evenly spread accross this side There's a special mode where you can have connections touch where columns are:

enter image description here

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Mike Lischke Avatar answered Oct 10 '22 07:10

Mike Lischke