MySQL Workbench - how to display relationships?

You need to open reverse engineer: Database->Reverse engineer CTRL+R

Complete the wizard. It ask about the database to connect and other simple questions.

Just click Next.

After wizard completion the MySQL Model tab will be opened. Click there ERR Diagram icon

When you edit a table in an EER model, you will have a tab named Foreign Keys that allows you to define well... the foreign keys. These foreign keys will be visible in the diagram.

You can change the settings for the displayed relationship by double clicking on the line that connects the tables.

You need to check draw line box.

I had an issue generated a PNG with the relationship lines.

Environment

• WorkBench version 8.0
• MacOS Mojave 10.14.5 with Dark Theme

Solution:

Disable dark theme and regenerate the diagram then export the PNG.