2157 words

javax.persistence.criteria.Subquery - JPA interface

javax.persistence.criteria
Interface Subquery<T>

Superinterfaces:
AbstractQuery<T>, Expression<T>, Selection<T>, TupleElement<T>
The Subquery interface defines functionality that is specific to subqueries. A subquery has an expression as its selection item.
Since:
JPA 2.0
Selection<X> alias(String name)
Assigns an alias to the selection item.
Assigns an alias to the selection item. Once assigned, an alias cannot be changed or reassigned. Returns the same selection item.
Parameters:
name - alias
Returns:
selection item
Since:
JPA 2.0
Expression<X> as(Class<X> type)
Perform a typecast upon the expression, returning a new expression object.
Perform a typecast upon the expression, returning a new expression object. This method does not cause type conversion: the runtime type is not changed. Warning: may result in a runtime failure.
Parameters:
type - intended type of the expression
Returns:
new expression of the given type
Since:
JPA 2.0
Create a subquery root correlated to a root of the enclosing query.
Create a subquery root correlated to a root of the enclosing query.
Parameters:
parentRoot - a root of the containing query
Returns:
subquery root
Since:
JPA 2.0
Create a subquery join object correlated to a join object of the enclosing query.
Create a subquery join object correlated to a join object of the enclosing query.
Parameters:
parentJoin - join object of the containing query
Returns:
subquery join
Since:
JPA 2.0
Create a subquery set join object correlated to a set join object of the enclosing query.
Create a subquery set join object correlated to a set join object of the enclosing query.
Parameters:
parentSet - join object of the containing query
Returns:
subquery join
Since:
JPA 2.0
Create a subquery map join object correlated to a map join object of the enclosing query.
Create a subquery map join object correlated to a map join object of the enclosing query.
Parameters:
parentMap - join object of the containing query
Returns:
subquery join
Since:
JPA 2.0
Create a subquery list join object correlated to a list join object of the enclosing query.
Create a subquery list join object correlated to a list join object of the enclosing query.
Parameters:
parentList - join object of the containing query
Returns:
subquery join
Since:
JPA 2.0
Create a subquery collection join object correlated to a collection join object of the enclosing query.
Create a subquery collection join object correlated to a collection join object of the enclosing query.
Parameters:
parentCollection - join object of the containing query
Returns:
subquery join
Since:
JPA 2.0
Subquery<T> distinct(boolean distinct)
Specify whether duplicate query results will be eliminated.
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.
Parameters:
distinct - boolean value specifying whether duplicate results must be eliminated from the subquery result or whether they must be retained
Returns:
the modified subquery.
Since:
JPA 2.0
AbstractQuery<T> distinct(boolean distinct)
Specify whether duplicate query results will be eliminated.
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.
Parameters:
distinct - boolean value specifying whether duplicate results must be eliminated from the query result or whether they must be retained
Returns:
the modified query
Since:
JPA 2.0
Root<X> from(Class<X> entityClass)
Create and add a query root corresponding to the given entity, forming a cartesian product with any existing roots.
Create and add a query root corresponding to the given entity, forming a cartesian product with any existing roots.
Parameters:
entityClass - the entity class
Returns:
query root corresponding to the given entity
Since:
JPA 2.0
Create and add a query root corresponding to the given entity, forming a cartesian product with any existing roots.
Create and add a query root corresponding to the given entity, forming a cartesian product with any existing roots.
Parameters:
entity - metamodel entity representing the entity of type X
Returns:
query root corresponding to the given entity
Since:
JPA 2.0
String getAlias()
Return the alias assigned to the tuple element or null, if no alias has been assigned.
Return the alias assigned to the tuple element or null, if no alias has been assigned.
Returns:
alias
Since:
JPA 2.0
Return the selection items composing a compound selection.
Return the selection items composing a compound selection. Modifications to the list do not affect the query.
Returns:
list of selection items
Throws:
IllegalStateException - if selection is not a compound selection
Since:
JPA 2.0
Return the correlated joins of the subquery.
Return the correlated joins of the subquery. Returns empty set if the subquery has no correlated joins. Modifications to the set do not affect the query.
Returns:
the correlated joins of the subquery
Since:
JPA 2.0
Return a list of the grouping expressions.
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.
Returns:
the list of grouping expressions
Since:
JPA 2.0
Return the predicate that corresponds to the restriction(s) over the grouping items, or null if no restrictions have been specified.
Return the predicate that corresponds to the restriction(s) over the grouping items, or null if no restrictions have been specified.
Returns:
having clause predicate
Since:
JPA 2.0
Class<?> getJavaType()
Return the Java type of the tuple element.
Return the Java type of the tuple element.
Returns:
the Java type of the tuple element
Since:
JPA 2.0
Return the query of which this is a subquery.
Return the query of which this is a subquery.
Returns:
the enclosing query or subquery
Since:
JPA 2.0
Return the predicate that corresponds to the where clause restriction(s), or null if no restrictions have been specified.
Return the predicate that corresponds to the where clause restriction(s), or null if no restrictions have been specified.
Returns:
where clause predicate
Since:
JPA 2.0
Class<T> getResultType()
Return the result type of the query or subquery.
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.
Returns:
result type
Since:
JPA 2.0
Return the query roots.
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.
Returns:
the set of query roots
Since:
JPA 2.0
Return the selection expression.
Return the selection expression.
Returns:
the item to be returned in the subquery result
Since:
JPA 2.0
Return the selection of the query, or null if no selection has been set.
Return the selection of the query, or null if no selection has been set.
Returns:
selection item
Since:
JPA 2.0
Specify the expressions that are used to form groups over the subquery results.
Specify the expressions that are used to form groups over the subquery 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.
Parameters:
grouping - list of zero or more grouping expressions
Returns:
the modified subquery
Since:
JPA 2.0
Specify the expressions that are used to form groups over the query results.
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.
Parameters:
grouping - list of zero or more grouping expressions
Returns:
the modified query
Since:
JPA 2.0
Specify the expressions that are used to form groups over the subquery results.
Specify the expressions that are used to form groups over the subquery 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.
Parameters:
grouping - zero or more grouping expressions
Returns:
the modified subquery
Since:
JPA 2.0
Specify the expressions that are used to form groups over the query results.
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.
Parameters:
grouping - zero or more grouping expressions
Returns:
the modified query
Since:
JPA 2.0
Specify restrictions over the groups of the subquery according the conjunction of the specified restriction predicates.
Specify restrictions over the groups of the subquery 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.
Parameters:
restrictions - zero or more restriction predicates
Returns:
the modified subquery
Since:
JPA 2.0
Specify a restriction over the groups of the subquery.
Specify a restriction over the groups of the subquery. Replaces the previous having restriction(s), if any. This method only overrides the return type of the corresponding AbstractQuery method.
Parameters:
restriction - a simple or compound boolean expression
Returns:
the modified subquery
Since:
JPA 2.0
Specify restrictions over the groups of the query according the conjunction of the specified restriction predicates.
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.
Parameters:
restrictions - zero or more restriction predicates
Returns:
the modified query
Since:
JPA 2.0
Specify a restriction over the groups of the query.
Specify a restriction over the groups of the query. Replaces the previous having restriction(s), if any.
Parameters:
restriction - a simple or compound boolean expression
Returns:
the modified query
Since:
JPA 2.0
Predicate in(Object... values)
Create a predicate to test whether the expression is a member of the argument list.
Create a predicate to test whether the expression is a member of the argument list.
Parameters:
values - values to be tested against
Returns:
predicate testing for membership
Since:
JPA 2.0
Predicate in(Collection<?> values)
Create a predicate to test whether the expression is a member of the collection.
Create a predicate to test whether the expression is a member of the collection.
Parameters:
values - collection of values to be tested against
Returns:
predicate testing for membership
Since:
JPA 2.0
Create a predicate to test whether the expression is a member of the collection.
Create a predicate to test whether the expression is a member of the collection.
Parameters:
values - expression corresponding to collection to be tested against
Returns:
predicate testing for membership
Since:
JPA 2.0
Create a predicate to test whether the expression is a member of the argument list.
Create a predicate to test whether the expression is a member of the argument list.
Parameters:
values - expressions to be tested against
Returns:
predicate testing for membership
Since:
JPA 2.0
Whether the selection item is a compound selection.
Whether the selection item is a compound selection.
Returns:
boolean indicating whether the selection is a compound selection
Since:
JPA 2.0
boolean isDistinct()
Return whether duplicate query results must be eliminated or retained.
Return whether duplicate query results must be eliminated or retained.
Returns:
boolean indicating whether duplicate query results must be eliminated
Since:
JPA 2.0
Create a predicate to test whether the expression is not null.
Create a predicate to test whether the expression is not null.
Returns:
predicate testing whether the expression is not null
Since:
JPA 2.0
Create a predicate to test whether the expression is null.
Create a predicate to test whether the expression is null.
Returns:
predicate testing whether the expression is null
Since:
JPA 2.0
Specify the item that is to be returned as the subquery result.
Specify the item that is to be returned as the subquery result. Replaces the previously specified selection, if any.
Parameters:
expression - expression specifying the item that is to be returned as the subquery result
Returns:
the modified subquery
Since:
JPA 2.0
Subquery<U> subquery(Class<U> type)
Create a subquery of the query.
Create a subquery of the query.
Parameters:
type - the subquery result type
Returns:
subquery
Since:
JPA 2.0
Modify the subquery to restrict the result according to the conjunction of the specified restriction predicates.
Modify the subquery to restrict the 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.
Parameters:
restrictions - zero or more restriction predicates
Returns:
the modified subquery
Since:
JPA 2.0
Modify the subquery to restrict the result according to the specified boolean expression.
Modify the subquery to restrict the 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.
Parameters:
restriction - a simple or compound boolean expression
Returns:
the modified subquery
Since:
JPA 2.0
Modify the query to restrict the query results according to the conjunction of the specified restriction predicates.
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.
Parameters:
restrictions - zero or more restriction predicates
Returns:
the modified query
Since:
JPA 2.0
Modify the query to restrict the query results according to the specified boolean expression.
Modify the query to restrict the query results according to the specified boolean expression. Replaces the previously added restriction(s), if any.
Parameters:
restriction - a simple or compound boolean expression
Returns:
the modified query
Since:
JPA 2.0

This documentation page is derived (with some adjustments) from the open source JPA 2 RI (EclipseLink)
and is available under the terms of the Eclipse Public License, v. 1.0 and Eclipse Distribution License, v. 1.0.
Object Relational Mapping (ORM) JPA 2 providers include Hibernate, EclipseLink, TopLink, OpenJPA and DataNucleus.
Object DB is not an ORM JPA implementation but an Object Database for Java with built in JPA 2 support.