Enum Attributes

The standard use of JPA for enum attributes involves an integer database field containing a value obtained from the ordinal() method. This approach may lead to the following issues with extending a system in production:

  • An entity instance cannot be loaded, if the value of the enum in the database does not equal to any ordinal value.

  • It is impossible to add a new value between the existing ones, which is important when sorting by enumeration value (order by).

CUBA-style approach to solving these problems is to detach the value stored in the database from ordinal value of the enumeration. In order to do this, the field of the entity should be declared with the type, stored in the database (Integer or String), while the access methods (getter / setter) should be created with the actual enumeration type.


@Entity(name = "sales$Customer")
@Table(name = "SALES_CUSTOMER")
public class Customer extends StandardEntity {

    @Column(name = "GRADE")
    protected Integer grade;

    public CustomerGrade getGrade() {
        return grade == null ? null : CustomerGrade.fromId(grade);

    public void setGrade(CustomerGrade grade) {
        this.grade = grade == null ? null : grade.getId();

In this case, the enumeration class can look like this:

public enum CustomerGrade implements EnumClass<Integer> {


    private Integer id;

    CustomerGrade(Integer id) {
        this.id = id;

    public Integer getId() {
        return id;

    public static CustomerGrade fromId(Integer id) {
        for (CustomerGrade grade : CustomerGrade.values()) {
            if (grade.getId().equals(id))
                return grade;
        return null;

For correct reflection in metadata, the enumeration class must implement the EnumClass interface.

As the examples show, grade attribute corresponds to the Integer type value stored in the database, which is specified by the id field of CustomerGrade enumeration, namely 10, 20 or 30. At the same time, the application code and metadata framework use CustomerGrade enum through access methods, which perform the actual conversion.

A call to getGrade() method will simply return null, if the value in the database does not correspond to any of the enumeration values. In order to add a new value, for example, HIGHER, between HIGH and PREMIUM, it is sufficient to add new enumeration value with id = 15, which ensures that sorting by Customer.grade field remains correct.

Enumerations can be created in CUBA Studio on the DATA MODEL tab (New → Enumeration). To be used as an entity attribute, choose ENUM in the Attribute type field of the attribute editor and select the Enumeration class in the Type field. Enumeration values can be associated with localized names that will be displayed in the user interface of the application.