Data in a table is usually organized into groups based on certain criteria. You can define multi-level groups in your table either when creating it or after the table has been built. In this section, you will be shown how to define groups in an existing table.
To group data of an existing table:
on the Insert toolbar.
to add it to the group by box (the box on the right). And if the type of the group by field is Numeric/String/Date/Time, you can select a special function for the field as required.One or more GH-GF (group header and group footer) row pairs with the selected group fields will have been added to the table.
The following are some specific topics about grouping: