Yes they are valid. Please click on the reference line, and click "Mandatory" checkbox on right panel
Reference name contains "space" character. Names with spaces are valid, but needs more attention while performing SQL queries. That's why there is a warning.
Sorry, there is no way to color columns.
Please attach example screenshot here.
I've switched you to Premium Trial account so you'll be able to join another company.
There are two options.
The first one. Please click on the XML button on main menu. You'll be able to download XML file.
If you want to incorporate downloading into your build system please check our documentation regarding using API:
Limits are for lifetime.
There is no option to create virtual class. You may use sharing option. Please create an empty model for each student and share it with her/him.
Hope it helps.
If your Facebook and Vertabelo account shares the same email address you may sign up using FB button.
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