Copyright (c) 2008 - 2013 Oracle Corporation. 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 2.1
    Linda DeMichiel - Java Persistence 2.0
/*******************************************************************************
 * Copyright (c) 2008 - 2013 Oracle Corporation. 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 2.1
 *     Linda DeMichiel - Java Persistence 2.0
 *
 ******************************************************************************/ 
package javax.persistence.criteria;

import java.util.List;
import java.util.Set;

The CriteriaQuery interface defines functionality that is specific 
to top-level queries.
Type parameters:
<T> –  the type of the defined result
Since:
Java Persistence 2.0/**
 * 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.
 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. 
    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"));

Params:
selection –  selection specifying the item that
       is to be returned in the query result
Throws:
IllegalArgumentException – if the selection is
        a compound selection and more than one selection 
        item has the same assigned alias
Returns:
the modified query/**
     * 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&#060;String&#062; q = cb.createQuery(String.class);
     *     Root&#060;Order&#062; order = q.from(Order.class);
     *     q.select(order.get("shippingAddress").&#060;String&#062;get("state"));
     * 
     *     CriteriaQuery&#060;Product&#062; q2 = cb.createQuery(Product.class);
     *     q2.select(q2.from(Order.class)
     *                 .join("items")
     *                 .&#060;Item,Product&#062;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.
 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, in the specified order, 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), 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, in the
specified order.  
 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,
in the specified order.

Params:
selections –  selection items corresponding to the
       results to be returned by the query
Throws:
IllegalArgumentException – if a selection item is
        not valid or if more than one selection item has
        the same assigned alias
Returns:
the modified query/**
     * 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&#060;Tuple&#062;</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&#060;X&#062;</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&#060;X[]&#062;</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&#060;Object&#062;</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&#060;Object&#062;</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.
 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, 
in the specified order, 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), 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,
in the specified order.  
 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, in the specified order.

Params:
selectionList –  list of selection items corresponding 
       to the results to be returned by the query
Throws:
IllegalArgumentException – if a selection item is
        not valid or if more than one selection item has
        the same assigned alias
Returns:
the modified query/**
     * 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&#060;Tuple&#062;</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&#060;X&#062;</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&#060;X[]&#062;</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&#060;Object&#062;</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&#060;Object&#062;</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 AbstractQuery method.
Params:
restriction –  a simple or compound boolean expression
Returns:
the modified query/**
     * 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 AbstractQuery method.
Params:
restrictions –  zero or more restriction predicates
Returns:
the modified query/**
     * 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 AbstractQuery method.
Params:
grouping –  zero or more grouping expressions
Returns:
the modified query/**
     * 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 AbstractQuery method.
Params:
grouping –  list of zero or more grouping expressions
Returns:
the modified query/**
     * 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 AbstractQuery method.
Params:
restriction –  a simple or compound boolean expression
Returns:
the modified query/**
     * 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 AbstractQuery method.
Params:
restrictions –  zero or more restriction predicates
Returns:
the modified query/**
     * 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.
Params:
o –  zero or more ordering expressions
Returns:
the modified query/**
     * 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.
Params:
o –  list of zero or more ordering expressions
Returns:
the modified query/**
     * 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 AbstractQuery method.
Params:
distinct –  boolean value specifying whether duplicate
       results must be eliminated from the query result or
       whether they must be retained
Returns:
the modified query./**
     * 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.
Returns:
the list of ordering expressions/**
     * 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.
Returns:
the query parameters/**
     * 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();
}