In phpMyAdmin it's really hard to see which column has been assigned PK. If base on the color of icon, it's doesn't make sense because I assume column with data type text have a grey icon.
1 Answers
In PhpMyadmin primary key identify by underline in column name.
In your case, you have underline in task_id.
other grey color means , you can't assign primary key to that column .
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