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/*******************************************************************************
* Copyright (c) 1998, 2009 Oracle. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* dclarke - Java Persistence 2.0 - Proposed Final Draft (March 13, 2009)
* Specification available from http://jcp.org/en/jsr/detail?id=317
* gyorke - Post PFD updates
*
* Java(TM) Persistence API, Version 2.0 - EARLY ACCESS
* This is an implementation of an early-draft specification developed under the
* Java Community Process (JCP). The code is untested and presumed not to be a
* compatible implementation of JSR 317: Java(TM) Persistence API, Version 2.0.
* We encourage you to migrate to an implementation of the Java(TM) Persistence
* API, Version 2.0 Specification that has been tested and verified to be compatible
* as soon as such an implementation is available, and we encourage you to retain
* this notice in any implementation of Java(TM) Persistence API, Version 2.0
* Specification that you distribute.
******************************************************************************/
package javax.persistence.criteria;
import java.util.List;
import java.util.Set;
/**
* The interface CriteriaQuery defines functionality that is specific to
* top-level queries.
*
* A top-level query has an ordered list of selections.
*/
public interface CriteriaQuery<T> extends AbstractQuery<T> {
/**
* Specify the item that is to be returned in the query result.
* Replaces the previously specified selection, if any.
* @param selection selection specifying the item that
* is to be returned in the query result
* @return the modified query
*/
CriteriaQuery<T> select(Selection<? extends T> selection);
/**
* Specify the selection items that are to be returned in the
* query result.
* Replaces the previously specified selection(s), if any.
*
* The type of the result of the query execution depends on
* the specification of the type of the criteria query object
* created as well as the arguments to the multiselect method.
* An argument to the multiselect method must not be a tuple-
* or array-valued compound selection item.
* The semantics of this method are as follows:
*
* If the type of the criteria query is CriteriaQuery<Tuple>
* (i.e., a criteria query object created by either the
* createTupleQuery method or by passing a Tuple class argument
* to the createQuery method), a Tuple object corresponding to
* the arguments of the multiselect method will be instantiated
* and returned for each row that results from the query execution.
*
* If the type of the criteria query is CriteriaQuery<X> for
* some user-defined class X (i.e., a criteria query object
* created by passing a X class argument to the createQuery
* method), then the arguments to the multiselect method will be
* passed to the X constructor and an instance of type X will be
* returned for each row.
*
* If the type of the criteria query is CriteriaQuery<X[]> for
* some class X, an instance of type X[] will be returned for
* each row. The elements of the array will correspond to the
* arguments of the multiselect method.
*
* If the type of the criteria query is CriteriaQuery<Object>
* or if the criteria query was created without specifying a type,
* and only a single argument is passed to the multiselect method,
* an instance of type Object will be returned for each row.
*
* If the type of the criteria query is CriteriaQuery<Object>
* or if the criteria query was created without specifying a type,
* and more than one argument is passed to the multiselect method,
* an instance of type Object[] will be instantiated and returned
* for each row. The elements of the array will correspond to the
* arguments to the multiselect method.
*
* @param selections selection items corresponding to the
* results to be returned by the query
* @return the modified query
*/
CriteriaQuery<T> multiselect(Selection<?>... selections);
/**
* Specify the selection items that are to be returned in the
* query result.
* Replaces the previously specified selection(s), if any.
*
* The type of the result of the query execution depends on
* the specification of the type of the criteria query object
* created as well as the argument to the multiselect method.
* An element of the list passed to the multiselect method
* must not be a tuple- or array-valued compound selection item.
* The semantics of this method are as follows:
*
* If the type of the criteria query is CriteriaQuery<Tuple>
* (i.e., a criteria query object created by either the
* createTupleQuery method or by passing a Tuple class argument
* to the createQuery method), a Tuple object corresponding to
* the elements of the list passed to the multiselect method
* will be instantiated and returned for each row that results
* from the query execution.
*
* If the type of the criteria query is CriteriaQuery<X> for
* some user-defined class X (i.e., a criteria query object
* created by passing a X class argument to the createQuery
* method), then the elements of the list passed to the
* multiselect method will be passed to the X constructor and
* an instance of type X will be returned for each row.
*
* If the type of the criteria query is CriteriaQuery<X[]> for
* some class X, an instance of type X[] will be returned for
* each row. The elements of the array will correspond to the
* elements of the list passed to the multiselect method.
*
* If the type of the criteria query is CriteriaQuery<Object>
* or if the criteria query was created without specifying a type,
* and the list passed to the multiselect method contains only
* a single element, an instance of type Object will be returned
* for each row.
*
* If the type of the criteria query is CriteriaQuery<Object>
* or if the criteria query was created without specifying a type,
* and the list passed to the multiselect method contains more
* than one element, an instance of type Object[] will be
* instantiated and returned for each row. The elements of the
* array will correspond to the elements of the list passed to
* the multiselect method.
*
* @param selectionList list of selection items corresponding
* to the results to be returned by the query
* @return the modified query
*/
CriteriaQuery<T> multiselect(List<Selection<?>> selectionList);
/**
* Modify the query to restrict the query result according
* to the specified boolean expression.
* Replaces the previously added restriction(s), if any.
* This method only overrides the return type of the
* corresponding AbstractQuery method.
* @param restriction a simple or compound boolean expression
* @return the modified query
*/
CriteriaQuery<T> where(Expression<Boolean> restriction);
/**
* Modify the query to restrict the query result 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. This
* method only overrides the return type of the corresponding AbstractQuery
* method.
*
* @param restrictions
* zero or more restriction predicates
* @return the modified query
*/
CriteriaQuery<T> 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. This method only overrides the return
* type of the corresponding AbstractQuery method.
*
* @param grouping
* zero or more grouping expressions
* @return the modified query
*/
CriteriaQuery<T> groupBy(Expression<?>... grouping);
/**
* Specify a restriction over the groups of the query. Replaces the previous
* having restriction(s), if any. This method only overrides the return type
* of the corresponding AbstractQuery method.
*
* @param restriction
* a simple or compound boolean expression
* @return the modified query
*/
CriteriaQuery<T> having(Expression<Boolean> restriction);
/**
* Specify restrictions over the groups of the query according 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. This
* method only overrides the return type of the corresponding AbstractQuery
* method.
*
* @param restrictions
* zero or more restriction predicates
* @return the modified query
*/
CriteriaQuery<T> having(Predicate... restrictions);
/**
* Specify the ordering expressions that are used to order the query
* results. Replaces the previous ordering expressions, if any. If no
* ordering expressions are specified, the previous ordering, if any, is
* simply removed, and results will be returned in no particular order. The
* left-to-right sequence of the ordering expressions determines the
* precedence, whereby the leftmost has highest precedence.
*
* @param o
* zero or more ordering expressions
* @return the modified query.
*/
CriteriaQuery<T> orderBy(Order... o);
/**
* 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. This method only overrides the return type of
* the corresponding AbstractQuery method.
*
* @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.
*/
CriteriaQuery<T> distinct(boolean distinct);
/**
* Return the result type of the query.
* If a result type was specified as an argument to the
* createQuery 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();
/**
* Return the ordering expressions in order of precedence.
*
* @return the list of ordering expressions
*/
List<Order> getOrderList();
/**
* Return the parameters of the query
*
* @return the query parameters
*/
Set<ParameterExpression<?>> getParameters();
}