Index a column using the icon, and toggle option like primary key, unique key etc

When creating new table all the columns by default is set to primary key, I was clicking on the key icon, I thought I can click it and toggle options  that allows to un-index other column but not.

And hope it has another additional options in the column null/not-null toggle 

that can set default value or defined value as (defined, none, null, not-null) 

But this is a great Application!

Thank you!