Annotations

Annotations are the basis for the communication between your application and LML. The are used for the engine to know about your entities, their relationships and how they are reflected in the database.

First of all, a summary of the annotations:

Name	Attributes	Description
PersistentEntity	String: tableName, updateControlAttribute, generateKey	Marks the entit as persistent
PersistentAttribute	columnName, primaryKey, associated, required, cascade	Marks an entity attribute as persistent
AssociatedEntityList	required, externalKey, cascade	Marks an entity attribute as an associated persistent entities list
AssociationType (enumeration)	NONE, OPTIONAL, REQUIRED	Enumeration which gruops different type of associations betweemn entities

PersistentEntity Detail

This annotation must be used to mark your domain entities who reflect a database table.

Attribute	Descripcion	Default value
tableName	String: Table name for this entity.	Empty string. The name of the class is used (uppercase)
updateControlAttribute	String: A dateTime attribute you use to check dirty updates	Empty string
generateKey	boolean: Tells the library to generate identifiers for this entity (true) or to leave that task to the database (false)	false (database generation)

PersistentAttribute Detail

You must use this annotation to mark the entity attributes that reflects table columns.

Attribute	Descripcion	Default value
columnName	String: Name of the corresponding table column.	Empty string. The name of the attribute is used (uppercase)
primaryKey	boolean: Is thie attribute the identifier for the entity?	false
entity	boolean: attribute is an associated entity	false
readAssociationType	AssociationType: What to do with this associated entity when main one is read	AssociationType.OPTIONAL
saveAssociationType	AssociationType: What to do with this associated entity when main one is created	AssociationType.NONE
updateAssociationType	AssociationType: What to do with this associated entity when this one is updated	AssociationType.OPTIONAL
removeAssociationType	AssociationType: What to do with this associated entity when this one is removed	AssociationType.NONE

AssociatedEntityList Detail

You must use this annotation to mark an attribute that is an associated entities list.

Attribute	Descripcion	Default value
externalKey	String: Name of the column in the assoiated table with the Foreign Key to main one	Required field
readAssociationType	AssociationType: What to do with this associated entity when main one is read	AssociationType.OPTIONAL
saveAssociationType	AssociationType: What to do with this associated entity when main one is created	AssociationType.NONE
updateAssociationType	AssociationType: What to do with this associated entity when this one is updated	AssociationType.OPTIONAL
removeAssociationType	AssociationType: What to do with this associated entity when this one is removed	AssociationType.NONE

CascadeType enumeration detail

Thie enumeration stores the association types entities use.

Name	Description
NONE	Associated entity or collection DOESN'T HAVE TO BE PERSISTED when main one does
OPTIONAL	Associated entity or collection must be persisted when main one does, but the operation does not have to be successful
REQUIRED	Associated entity or collection must be persisted when main one does, and the operation have to be successful

Exsample

Annotated POJO sample:

@PersistentEntity(tableName="CUSTOMER", generateKey=true)
public class Customer implements Serializable {
 
    @PersistentAttribute(primaryKey=true, columnName="customer_id")
    private Integer customerId;
 
    @PersistentAttribute(columnName = "ZIP")
    private String zip;
 
    @PersistentAttribute(columnName = "NAME")
    private String name;
 
    @PersistentAttribute(columnName = "ADDRESSLINE1")
    private String addressLine1;
 
    @PersistentAttribute(columnName = "ADDRESSLINE2")
    private String addressLine2;
 
    @PersistentAttribute // It's not necessary to write column name when its equal to attribute name
    private String city;
 
    @PersistentAttribute(columnName = "STATE")
    private String state;
 
    @PersistentAttribute(columnName = "PHONE")
    private String phone;
 
    @PersistentAttribute(columnName = "FAX")
    private String fax;
 
    @PersistentAttribute(columnName = "EMAIL")
    private String email;
 
    @PersistentAttribute(columnName = "CREDIT_LIMIT")
    private Integer creditLimit;
 
    @PersistentAttribute(columnName = "DISCOUNT_CODE", entity=true, readAssociationType=AssociationType.REQUIRED, 
         updateAssociationType=AssociationType.NONE)
    private DiscountCode discountCode;
 
    @AssociatedEntityList(externalKey="CUSTOMER_id", saveAssociationType=AssociationType.OPTIONAL, 
         removeAssociationType=AssociationType.REQUIRED)
    private Collection<PurchaseOrder> purchaseOrders;
 
    public Customer() {
    }
}