javax.persistence.criteria.AbstractQuery Maven / Gradle / Ivy
// $Id: AbstractQuery.java 17752 2009-10-15 01:19:21Z [email protected] $
// EJB3 Specification Copyright 2004-2009 Sun Microsystems, Inc.
package javax.persistence.criteria;
import java.util.List;
import java.util.Set;
import javax.persistence.metamodel.EntityType;
/**
* The AbstractQuery interface defines functionality that is common
* to both top-level queries and subqueries.
* It is not intended to be used directly in query construction.
*
* All queries must have:
* a set of root entities (which may in turn own joins).
*
All queries may have:
* a conjunction of restrictions.
*
* @param the type of the result
* @since Java Persistence 2.0
*/
public interface AbstractQuery {
/**
* Create and add a query root corresponding to the given entity,
* forming a cartesian product with any existing roots.
*
* @param entityClass the entity class
*
* @return query root corresponding to the given entity
*/
Root from(Class entityClass);
/**
* Create and add a query root corresponding to the given entity,
* forming a cartesian product with any existing roots.
*
* @param entity metamodel entity representing the entity
* of type X
*
* @return query root corresponding to the given entity
*/
Root from(EntityType entity);
/**
* Modify the query to restrict the query results according
* to the specified boolean expression.
* Replaces the previously added restriction(s), if any.
*
* @param restriction a simple or compound boolean expression
*
* @return the modified query
*/
AbstractQuery where(Expression restriction);
/**
* Modify the query to restrict the query results according
* to the conjunction of the specified restriction predicates.
* Replaces the previously added restriction(s), if any.
* If no restrictions are specified, any previously added
* restrictions are simply removed.
*
* @param restrictions zero or more restriction predicates
*
* @return the modified query
*/
AbstractQuery where(Predicate... restrictions);
/**
* Specify the expressions that are used to form groups over
* the query results.
* Replaces the previous specified grouping expressions, if any.
* If no grouping expressions are specified, any previously
* added grouping expressions are simply removed.
*
* @param grouping zero or more grouping expressions
*
* @return the modified query
*/
AbstractQuery groupBy(Expression... grouping);
/**
* Specify the expressions that are used to form groups over
* the query results.
* Replaces the previous specified grouping expressions, if any.
* If no grouping expressions are specified, any previously
* added grouping expressions are simply removed.
*
* @param grouping list of zero or more grouping expressions
*
* @return the modified query
*/
AbstractQuery groupBy(List> grouping);
/**
* Specify a restriction over the groups of the query.
* Replaces the previous having restriction(s), if any.
*
* @param restriction a simple or compound boolean expression
*
* @return the modified query
*/
AbstractQuery having(Expression restriction);
/**
* Specify restrictions over the groups of the query
* according the conjunction of the specified restriction
* predicates.
* Replaces the previously having added restriction(s), if any.
* If no restrictions are specified, any previously added
* restrictions are simply removed.
*
* @param restrictions zero or more restriction predicates
*
* @return the modified query
*/
AbstractQuery having(Predicate... restrictions);
/**
* Specify whether duplicate query results will be eliminated.
* A true value will cause duplicates to be eliminated.
* A false value will cause duplicates to be retained.
* If distinct has not been specified, duplicate results must
* be retained.
*
* @param distinct boolean value specifying whether duplicate
* results must be eliminated from the query result or
* whether they must be retained
*
* @return the modified query
*/
AbstractQuery distinct(boolean distinct);
/**
* Create a subquery of the query.
*
* @param type the subquery result type
*
* @return subquery
*/
Subquery subquery(Class type);
/**
* Return the query roots. These are the roots that have
* been defined for the CriteriaQuery or Subquery itself,
* including any subquery roots defined as a result of
* correlation. Returns empty set if no roots have been defined.
* Modifications to the set do not affect the query.
*
* @return the set of query roots
*/
Set> getRoots();
/**
* Return the selection of the query, or null if no selection
* has been set.
*
* @return selection item
*/
Selection getSelection();
/**
* Return the predicate that corresponds to the where clause
* restriction(s), or null if no restrictions have been
* specified.
*
* @return where clause predicate
*/
Predicate getRestriction();
/**
* Return a list of the grouping expressions. Returns empty
* list if no grouping expressions have been specified.
* Modifications to the list do not affect the query.
*
* @return the list of grouping expressions
*/
List> getGroupList();
/**
* Return the predicate that corresponds to the restriction(s)
* over the grouping items, or null if no restrictions have
* been specified.
*
* @return having clause predicate
*/
Predicate getGroupRestriction();
/**
* Return whether duplicate query results must be eliminated or
* retained.
*
* @return boolean indicating whether duplicate query results
* must be eliminated
*/
boolean isDistinct();
/**
* Return the result type of the query or subquery. If a result
* type was specified as an argument to the
* createQuery or subquery method, that
* type will be returned. If the query was created using the
* createTupleQuery method, the result type is
* Tuple. Otherwise, the result type is
* Object.
*
* @return result type
*/
Class getResultType();
}