If you want to setup current field as a key one, you need to fill KEY with ‘X’. When you’ll do this then the field will have blue background and during horizontal scrolling the column will be fixed.
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The description of this fields claims that if you put ‘X’ inside then current field will became a key field that can be hidden, but in fact it has no effect here, as standard key field can always be hidden. ...
Field catalog is one of most important tables that is used in ALV Grid. In most cases you’ll create it manually or at least after automatic creation, you’ll update its content, as most of the columns settings ...