/*
* Copyright (c) 2008, 2009 Sun Microsystems. 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:
* Linda DeMichiel - Java Persistence 2.0 - Version 2.0 (October 1, 2009)
* Specification available from http://jcp.org/en/jsr/detail?id=317
*/
// $Id: CriteriaQuery.java 20957 2011-06-13 09:58:51Z stliu $
package javax.persistence.criteria;
import java.util.List;
import java.util.Set;
/**
* The <code>CriteriaQuery</code> interface defines functionality that is specific
* to top-level queries.
*
* @param <T> the type of the defined result
* @since Java Persistence 2.0
*/
public interface CriteriaQuery<T> extends AbstractQuery<T> {
/**
* Specify the item that is to be returned in the query result.
* Replaces the previously specified selection(s), if any.
*
* <p> Note: Applications using the string-based API may need to
* specify the type of the select item when it results from
* a get or join operation and the query result type is
* specified.
*
* <pre>
* For example:
*
* CriteriaQuery<String> q = cb.createQuery(String.class);
* Root<Order> order = q.from(Order.class);
* q.select(order.get("shippingAddress").<String>get("state"));
*
* CriteriaQuery<Product> q2 = cb.createQuery(Product.class);
* q2.select(q2.from(Order.class)
* .join("items")
* .<Item,Product>join("product"));
*
* </pre>
*
* @param selection selection specifying the item that
* is to be returned in the query result
*
* @return the modified query
*
* @throws IllegalArgumentException if the selection is
* a compound selection and more than one selection
* item has the same assigned alias
*/
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.
* <p> An argument to the multiselect method must not be a tuple-
* or array-valued compound selection item.
*
* <p>The semantics of this method are as follows:
* <ul>
* <li>
* If the type of the criteria query is
* <code>CriteriaQuery<Tuple></code> (i.e., a criteria
* query object created by either the
* <code>createTupleQuery</code> method or by passing a
* <code>Tuple</code> class argument to the
* <code>createQuery</code> method), a <code>Tuple</code> object
* corresponding to the arguments of the <code>multiselect</code>
* method, in the specified order, will be instantiated and
* returned for each row that results from the query execution.
*
* <li> If the type of the criteria query is <code>CriteriaQuery<X></code> for
* some user-defined class X (i.e., a criteria query object
* created by passing a X class argument to the <code>createQuery</code>
* method), the arguments to the <code>multiselect</code> method will be
* passed to the X constructor and an instance of type X will be
* returned for each row.
*
* <li> If the type of the criteria query is <code>CriteriaQuery<X[]></code> 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 <code>multiselect</code> method, in the
* specified order.
*
* <li> If the type of the criteria query is <code>CriteriaQuery<Object></code>
* or if the criteria query was created without specifying a
* type, and only a single argument is passed to the <code>multiselect</code>
* method, an instance of type <code>Object</code> will be returned for
* each row.
*
* <li> If the type of the criteria query is <code>CriteriaQuery<Object></code>
* or if the criteria query was created without specifying a
* type, and more than one argument is passed to the <code>multiselect</code>
* method, an instance of type <code>Object[]</code> will be instantiated
* and returned for each row. The elements of the array will
* correspond to the arguments to the <code> multiselect</code> method,
* in the specified order.
* </ul>
*
* @param selections selection items corresponding to the
* results to be returned by the query
*
* @return the modified query
*
* @throws IllegalArgumentException if a selection item is
* not valid or if more than one selection item has
* the same assigned alias
*/
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.
*
* <p> 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 <code>multiselect</code> method.
* An element of the list passed to the <code>multiselect</code> method
* must not be a tuple- or array-valued compound selection item.
*
* <p> The semantics of this method are as follows:
* <ul>
* <li> If the type of the criteria query is <code>CriteriaQuery<Tuple></code>
* (i.e., a criteria query object created by either the
* <code>createTupleQuery</code> method or by passing a <code>Tuple</code> class argument
* to the <code>createQuery</code> method), a <code>Tuple</code> object corresponding to
* the elements of the list passed to the <code>multiselect</code> method,
* in the specified order, will be instantiated and returned for each
* row that results from the query execution.
*
* <li> If the type of the criteria query is <code>CriteriaQuery<X></code> for
* some user-defined class X (i.e., a criteria query object
* created by passing a X class argument to the <code>createQuery</code>
* method), the elements of the list passed to the <code>multiselect</code>
* method will be passed to the X constructor and an instance
* of type X will be returned for each row.
*
* <li> If the type of the criteria query is <code>CriteriaQuery<X[]></code> 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 <code>multiselect</code> method,
* in the specified order.
*
* <li> If the type of the criteria query is <code>CriteriaQuery<Object></code>
* or if the criteria query was created without specifying a
* type, and the list passed to the <code>multiselect</code> method contains
* only a single element, an instance of type <code>Object</code> will be
* returned for each row.
*
* <li> If the type of the criteria query is <code>CriteriaQuery<Object></code>
* or if the criteria query was created without specifying a
* type, and the list passed to the <code>multiselect</code> method contains
* more than one element, an instance of type <code>Object[]</code> will be
* instantiated and returned for each row. The elements of the
* array will correspond to the elements of the list passed to
* the <code>multiselect</code> method, in the specified order.
* </ul>
*
* @param selectionList list of selection items corresponding
* to the results to be returned by the query
*
* @return the modified query
*
* @throws IllegalArgumentException if a selection item is
* not valid or if more than one selection item has
* the same assigned alias
*/
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 <code>AbstractQuery</code> 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 <code>AbstractQuery</code> 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 <code>AbstractQuery</code> method.
*
* @param grouping zero or more grouping expressions
*
* @return the modified query
*/
CriteriaQuery<T> 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.
* This method only overrides the return type of the
* corresponding <code>AbstractQuery</code> method.
*
* @param grouping list of zero or more grouping expressions
*
* @return the modified query
*/
CriteriaQuery<T> groupBy(List<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 <code>AbstractQuery</code> 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 having 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 <code>AbstractQuery</code> 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 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 order of the ordering expressions in the list
* determines the precedence, whereby the first element in the
* list has highest precedence.
*
* @param o list of zero or more ordering expressions
*
* @return the modified query
*/
CriteriaQuery<T> orderBy(List<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 <code>AbstractQuery</code> 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 ordering expressions in order of precedence.
* Returns empty list if no ordering expressions have been
* specified.
* Modifications to the list do not affect the query.
*
* @return the list of ordering expressions
*/
List<Order> getOrderList();
/**
* Return the parameters of the query. Returns empty set if
* there are no parameters.
* Modifications to the set do not affect the query.
*
* @return the query parameters
*/
Set<ParameterExpression<?>> getParameters();
}