Navicat provides a powerful tool to create models.
To convert existing tables and views into a model, you can right-click a database or schema and select “Reverse Database to Model...” or “Reverse Schema to Model...” from the popup menu.
Alternatively you can right-click the selected tables or views and select ”Reverse Tables to Model...” or ”Reverse Views to Model...” from the popup menu.
When you’ve finished designing the model, you can put it back to the existing database. Select “Synchronize to Database” in “Tools” from the menu.