mySQL (phpMyAdmin) error : This table does not contain a unique column
If you face this error in phpMyAdmin and you can't change/edit the table fields.
If you sure you got error like this :
"This table does not contain a unique column. Grid edit, checkbox, Edit, Copy and Delete features are not available."
So please execute next SQL query:
ALTER TABLE [tablename] add newid INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY FIRST;
You can execute the query from GUI of phpMyAdmin or from SSH CLI using mysql command first.