Fast Object Database for Java - with JPA/JDO support

Internal Website Search

1-10 of 180 resultsRefresh


javax.persistence.criteria Interface Root Superinterfaces: Expression, FetchParent, From, Path, Selection, TupleElement A root type in the from clause. Query roots always reference entities. Since: JPA 2.0 Learn how to use JPA criteria API's Root in Chapter 4


Method javax.jdo.FetchPlan FetchPlan setDetachmentRoots( Collection roots ) Set the roots for DetachAllOnCommit. Parameters: roots - Collection of the detachment roots. Since: JDO 2.0


Method javax.persistence.criteria.Root EntityType getModel() Return the metamodel entity corresponding to the root. Returns: metamodel entity corresponding to the root Since: JPA 2.0

Criteria Query From Elements

(bound by an entity class) are represented by the Root subinterface: Join variables (bound by

[ODB1] Chapter 9 - ObjectDB Explorer

information about the database and the bottom sub window displays a list of root objects that the database contains (root objects are discussed in chapter 6). The "Query" window enables a user to execute JDOQL ... all the instances of that class. Select a root object in the "Database" tabbed window to view the content

FROM clause (JPQL / Criteria API)

variable that serves as a root and additional join variables that are bound to path expressions ... are represented by the Root interface. Join variables are represented by the Join interface (and its sub interfaces). Criteria Query Roots The CriteriaQuery's from method serves as a factory of Root

Low performance when getting grove roots

Hi, I have a grove-like structure of objects, every objects referencing its parent. Root objects have null as the value of this parent reference. To find the roots I execute a query. If the number of objects in the tree is significant, this query takes almost forever, it seems ObjectDB loads



[ODB1] Chapter 6 - Persistent Objects

. Objects with names are called root objects in object databases, because navigation in the database ... directly by using its object ID. A root object can also be retrieved by its name. It is also possible ... A root object, which is a database object with an assigned name, can be retrieved by using its name

Paths and Types in JPQL and Criteria API

are represented in the JPA Criteria API by the Path interface and by its subinterfaces (From, Root, Join and Join's descendants). Path Expressions The Root and Join interfaces (which are subinterfaces ... field or property), can be constructed by the get method: // FROM Variable Paths: Root

Getting Started

ObjectDB is very easy to use. Follow the Getting Started Tutorial and the Quick Tour manual chapter and in minutes you may be able to write and run first Java programs against ObjectDB.

Prior knowledge or experience in database programming (SQL, JDBC, ORM, JPA, etc.) is not required, but some background in using the Java language is essential.

Need Help?

  1. Search ObjectDB website
  2. Read the FAQ
  3. Follow the Tutorials
  4. View or post in the forum
  5. Search or file an issue
  6. Contact support