DbMySQLQuery.resultFieldStringValueByName(): MySQL_ResultSet::isNull: invalid value of ‘columnLabel’

The proposed solution “[3 Feb 16:10] Adam Latchem” worked for me, in the context of MySQL Workbench connecting to a MariaDB database. The fix (for definiteness) is to edit the file C:\Program Files\MySQL\MySQL Workbench 8.0 CE\modules\wb_admin_connections.py at line 346, to change it from

("DB", mforms.StringColumnType, "DB", 100),


("db", mforms.StringColumnType, "DB", 100),

(note change of case in first argument).