I have spent some time trying to find this out, but can't find it in the docs, and google couldn't help so maybe something else?
I renamed one of my colums from type -> role in mysql, and then everything stoped. This is the message:
PDOException: SQLSTATE[42S22]: Column not found: 1054 Unknown column 'user.type' in 'field list'
Would be thankfull for some help, and would love to help others with the same problem!