# Package org.apache.cayenne.exp

package org.apache.cayenne.exp
Cayenne data expression classes.

This package contains classes that describe expression language of Cayenne. Cayenne expressions define expressions on objects rather than expressions on data. Other parts of Cayenne may translate them to the target database SQL syntax.

- Related Packages
  Package
  Description
  org.apache.cayenne
  Contains persistence APIs directly accessible by users.
  org.apache.cayenne.exp.parser
  Contains expression parser and other expression internals.
  org.apache.cayenne.exp.property
  Property API
- Class
  Description
  Expression
  Superclass of Cayenne expressions that defines basic API for expressions use.
  ExpressionException
  RuntimeException thrown on errors during expressions creation/parsing.
  ExpressionFactory
  Helper class to build expressions.
  ExpressionParameter
  Named parameter for parameterized expressions.
  FunctionExpressionFactory
  Collection of factory methods to create function call expressions.
  Property<E>
  Deprecated.
  since 4.2 in favour of type-specific set of properties, see `PropertyFactory` and `org.apache.cayenne.exp.property` package.
  TraversalHandler
  Expression visitor interface.
  TraversalHelper
  Noop implementation of TraversalHandler.
  ValueInjector
  Describes expressions, that can "inject" value to an object, i.e.