Select column / control
The desired data group can be selected here.
The name of the data field is shown here.
"Data type" column
The data types of the data fields are shown here.
"Control type" column
Clicking in this column will open a drop-down list where the control type can be selected.
Display already used data fields
If this setting is not active, you can only choose from the data fields that are not already in one of the table's columns or included as a control. If this setting is activated, all of the selectable fields will be shown.