Consider a numeric CollectionOfElements held by a class Product such as:
@Entity(name="Product")public class Product {protected Set serialNumbers = new HashSet();@CollectionOfElements@JoinTable(name="product_serialnumbers")public Set getSerialNumbers() { return serialNumbers;}public void setSerialNumbers(Set serialNumbers) { this.serialNumbers = serialNumbers;}}You can use a NamedQuery to determine the maximum SerialNumber held by any Product like this:
@Entity(name="Product")@NamedQueries ({ @NamedQuery( name = "maxSerialNumber", query = "select max(elements(p.serialNumbers)) as value from Product p" )})public class Product {protected Set serialNumbers = new HashSet();@CollectionOfElements@JoinTable(name="product_serialnumbers")public Set getSerialNumbers() { return serialNumbers;}public void setSerialNumbers(Set serialNumbers) { this.serialNumbers = serialNumbers;}}