field-name

only one 

Specifies the Java identifier of a field. This identifier must match the value of the field-name subelement of the cmp-field that is being mapped.

column-name

one or more 

Specifies the name of a column from the primary table, or the qualified table name (TABLE.COLUMN) of a column from a secondary or related table. 

read-only

zero or one 

Specifies that a field is read-only. 

fetched-with

zero or one 

Specifies the fetch group for this CMP field’s mapping.