This tag is for questions related to the Java Persistence Criteria API (from JPA 2.0) which is used to define queries through the construction of object-based query definition objects, rather than use of the string-based approach of the Java Persistence query language. For questions related to (N)Hibernate Criteria, use the [icriteria] tag.
Quoting the Overview from the JPA 2.0 Specification:
6.1 Overview
The Java Persistence Criteria API, like the Java Persistence query language is based on the abstract persistence schema of entities, their embedded objects, and their relationships as its data model. This abstract persistence schema is materialized in the form of metamodel objects over which the Criteria API operates. The semantics of criteria queries are designed to reflect those of Java Persistence query language queries.
The syntax of the Criteria API is designed to allow the construction of an object-based query “graph”, whose nodes correspond to the semantic query elements.
Java language variables can be used to reference individual nodes in a criteria query object as it is constructed and/or modified. Such variables, when used to refer to the entities and embeddable types that constitute the query domain, play a role analogous to that of the identification variables of the Java Persistence query language.
These concepts are further described in the sections that follow. The metamodel on which criteria queries are based is presented in Chapter 5. The static metamodel classes that can be used in constructing strongly-typed criteria queries are described in section 6.2. The
javax.persistence.criteriainterfaces are presented in Section 6.3. Sections 6.4 through 6.8 describe the construction and modification of criteria query objects. Additional requirements on the persistence provider are described in section 6.9.
