Helpo de LibreOffice 7.5
Specifies a field in the table to be used as a primary key.
Select to create a primary key. Add a primary key to every database table to uniquely identify each record. For some database systems within LibreOffice, a primary key is mandatory for editing the tables.
Select to automatically add a primary key as an additional field.
Select to use an existing field with unique values as a primary key.
Select the field name.
Select to automatically insert a value and increment the field's value for each new record. The database must support automatic incrementation in order to use the Auto value feature.
Select to create a primary key from a combination of several existing fields.
Select a field and click > to add it to the list of primary key fields.
Select a field and click < to remove it from the list of primary key fields. The primary key is created as a concatenation of the fields in this list, from top to bottom.