About identifier
FROM clause (JPQL / Criteria API)
Explains how to use the FROM clause and JOIN expressions in a JPA/JPQL query.... The name of a JPQL query variable must a valid Java identifier but cannot be one of the following reserved words: ABS, ...
javax.persistence.metamodel.IdentifiableType
Instances of the type IdentifiableType represent entity or mapped superclass types.(Interface of JPA)
javax.persistence.metamodel.MappedSuperclassType
Instances of the type MappedSuperclassType represent mapped superclass types.(Interface of JPA)
javax.persistence.metamodel.EntityType
Instances of the type EntityType represent entity types.(Interface of JPA)
getSupertype()
Return the identifiable type that corresponds to the most specific mapped superclass or entity extended by the entity or mapped superclass.(Method of javax.persistence.metamodel.IdentifiableType)
hasVersionAttribute()
Whether the identifiable type has a version attribute.(Method of javax.persistence.metamodel.IdentifiableType)
hasSingleIdAttribute()
Whether the identifiable type has a single id attribute.(Method of javax.persistence.metamodel.IdentifiableType)
javax.jdo.Query
The Query interface allows applications to obtain persistent instances, values, and aggregate data from the data store.(Interface of JDO)
JPA Metamodel API
Explains how to use the JPA Metamodel API to retrieve details on the types and attributes of the persistent object model. The JPA Metamodel API provides the ability to examine the persistent object model and retrieve details on managed classes and persistent fields and properties, similarly to the ability that Java reflection provides for general Java types. ...
javax.jdo.spi.PersistenceCapable
A class that can be managed by a binary-compatible JDO implementation must implement this interface.(Interface of JDO)
