Open MySQL Workbench. In the home screen click 'Create EER Model From Existing Database'. We are doing this for the case that we have already made the data base and now we want to make an ER diagram of that database.
Then you will see the 'Reverse Engineer Database' dialouge. Here if you are asked for the password, provided the admin password. Do not get confused here with the windows password. Here you need to provide the MySQL admin password. Then click on Next.
In the next dialouge box, you'll see that the connection to DBMS is started and schema is revrieved from Database. Go next.
Now Select the Schema you created earlier. It is the table you want to create the ER diagram of.
Click Next and go to Select Objects menu. Here you can click on 'Show Filter' to use the selected Table Objects in the diagram. You can both add and remove tables here.Then click on Execute.
6.When you go Next and Finish, the required ER diagram is on the screen.