Java API - OElement

This class provides a standard interface for handling documents, vertices and edges.

Managing Elements

When using OrientDB as a Document database, this class represents a document record. When using OrientDB as a Graph database, this is the superclass to the OVertex and OEdge classes, which represent vertices and edges in the database.

NOTE: In older versions of OrientDB, documents were represented using the ODocument class. While this class is still around and is the primary implementation of OElement, it is recommended that you do not use it directly. Instead, moving forward use OElement for your documents.

This class is available at com.orientechnologies.orient.core.record. To import it, use the following line where necessary:

import com.orientechnologies.orient.core.record.OElement;

Once you've imported the class to your application, you can use it to build particular instances in your code.

Example

In order to create a new instance of this class, it is recommended that you use either newInstance() or newElement() methods on the ODatabaseDocument class interface. This allows you to operate on the given record and easily save it back to the database when you're ready.

For instance, imagine you have a Map of variables containing a address book, where the key is the person's name and the value their email address, both as string values. You might use a method like this to transfer that data into OrientDB documents.

// INITIALIZE GLOBAL VARIABLES
private ODatabaseDocument db;
...

// ADD ENTRIES TO ADDRESSBOOK DATABASE
public void initAddressBook(Map<String, String> addressBook){

   // Loop Over Map
   for (Map.Entry<String, String> entry : addressBook.entrySet()){

      // Initialize Variables
	  String name = entry.getKey();
	  String email = entry.getKey();

	  // Create Person 
	  OElement person = db.newElement("Person");
	  person.setProperty("name", name);
	  person.setProperty("email", email);
	  
	  // Make Person Persistent
	  person.save();

   }
}

Methods

Once you've created or initialized an OElement instance, you can begin to call methods on the instance to further define and read data from the record.

Method	Return Type	Description
`asEdge()`	`Optional<OEdge>`	Returns record as an edge
`asVertex()`	`Optional<OVertex>`	Returns record as a vertex
`getProperty()`	`<RET> RET`	Retrieves record data by property name
`getPropertyNames()`	`Set<String>`	Retrieves defined property names
`getSchemaType()`	`Optional<OClass>`	Retrieves the type of the current element, (that is, class in the schema, if any)
`isEdge()`	`Boolean`	Determines whether record is an edge
`isVertex()`	`Boolean`	Determines whether record is a vertex
`removeProperty()`	`<RET> RET`	Removes a property from the record
`save()`	`<RET extends ORecord> RET`	Saves changes to OrientDB record
`setProperty()`	`void`	Sets data on record property

Saving Elements

When you create or retrieve an OElement instance, you create a snapshot of the record. Any changes you make to the record remain in your application. In order to make these changes persistent on the database, you need to call the save() method on the element. For instance,

// GLOBAL VARIABLES
private ODatabaseDocument db;

// CREATE NEW RECORD
public void newRecord(String name, String email){

   // Initialize Document
   OElement person = db.newElement("Person");
   person.setProperty("name", name);
   person.setProperty("email", email);

   // Add Person to Database
   person.save();
}