Entity Object is n object oriented
representation of data base objects like table. It represents a table or view.
It encapsulates the properties of a Row like the validation rules, security and
presenting values. It is used to perform all the DML operations.
Files related to
Entity Object
- Entity definition XML file-
Defines the structure of the entity
object. It acts as a template for the creation of entity objects.
- Entity Object class - It
represents an entity instance. It wraps the business logic for a row like
having default values at the time of row creation, lock() method to lock
the row and doDML() method to perform DML operations.
- Entity Collection Class- Caches the rows particular to a DB transaction.
Use the below code
to create the entity rows. You can have it in the Application module
implementation classes.
Creating a new entity row
public
void createEntityObject(){
EntityDefImpl
sampleEODef=sampleEOImpl.getDefinitionObject();//Here get the definition object
using the EOImpl like EntityImpl
SampleEOImpl
newEOInstance=sampleEODef.createInstance2(this.getDBTransaction(), null);
//The
entity status is STATUS_NEW now and qualifies to participate in a transaction.
//Use
the newEOInstance object to set the attribute values.
}
Finding an entity row and updating it
public
void updateEntity(String primaryKey){
//Key
creation by passing the primary key
Key
key= SampleEOImpl.createPrimaryKey(primaryKey);
//get
the definition object
//The
row status here is STATUS_UNMODIFIED now
EntityEOImpl
rowTobeUpdated =
(DepartmentEOImpl)SampleEOImpl.
getDefinitionObject().
findByPrimaryKey(getDBTransaction(),
key);
rowTobeUpdated
.setAttributes()
//The
row status here is STATUS_MODIFIED and qualifies for row the transaction.
}
Removing an entity row
The
below method takes a key attribute value in a row as input and performs find
and delete operations.
public
void removeEntity(Integer key){
//Key
creation by passing the key
Key
key= SampleEOImpl.createPrimaryKey(key);
EntityEOImpl
rowTobeDelted =
(SampleEOImpl)SampleEOImpl.
getDefinitionObject().
findByPrimaryKey(getDBTransaction(),
key);
//Row
status is STATUS_UNMODIFIED
rowTobeDelted.remove();
//Row
status is STATUS_DELETED
}
Committing a transaction
public
void commitTransaction(){
getDBTransaction().commit();
}
