I want to link a foregin key to a primary key of a different table. In order to do that with the gui I have to click on "Propose table structure". But then I get this error:
Current selection does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available.
I don't understand it, because I have an unique primary key. However, according to this question the following line will supress the error but doesn't explain, why the primary key isn't recognized.
$cfg['RowActionLinksWithoutUnique'] = true
This is my table