javax.persistence.criteria

Interface Expression<T>

Type Parameters:

T - the type of the expression

All Superinterfaces:

Selection<T>, TupleElement<T>

All Known Subinterfaces:

CollectionJoin<Z,E>, CriteriaBuilder.Case<R>, CriteriaBuilder.Coalesce<T>, CriteriaBuilder.In<T>, CriteriaBuilder.SimpleCase<C,R>, From<Z,X>, Join<Z,X>, ListJoin<Z,E>, MapJoin<Z,K,V>, ParameterExpression<T>, Path<X>, PluralJoin<Z,C,E>, Predicate, Root<X>, SetJoin<Z,E>, Subquery<T>

public interface Expression<T>
extends Selection<T>

Type for query expressions.

Since:

Java Persistence 2.0

Method Summary

Modifier and Type	Method and Description
<X> Expression<X>	as(Class<X> type) Perform a typecast upon the expression, returning a new expression object.
Predicate	in(Collection<?> values) Create a predicate to test whether the expression is a member of the collection.
Predicate	in(Expression<?>... values) Create a predicate to test whether the expression is a member of the argument list.
Predicate	in(Expression<Collection<?>> values) Create a predicate to test whether the expression is a member of the collection.
Predicate	in(Object... values) Create a predicate to test whether the expression is a member of the argument list.
Predicate	isNotNull() Create a predicate to test whether the expression is not null.
Predicate	isNull() Create a predicate to test whether the expression is null.

Methods inherited from interface javax.persistence.criteria.Selection

alias, getCompoundSelectionItems, isCompoundSelection

Methods inherited from interface javax.persistence.TupleElement

getAlias, getJavaType

Method Detail

isNull

Predicate isNull()

Create a predicate to test whether the expression is null.

Returns:

predicate testing whether the expression is null

isNotNull

Predicate isNotNull()

Create a predicate to test whether the expression is not null.

Returns:

predicate testing whether the expression is not null

in

Predicate in(Object... values)

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

in

Predicate in(Expression<?>... values)

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

in

Predicate in(Collection<?> values)

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

in

Predicate in(Expression<Collection<?>> values)

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

as

<X> Expression<X> as(Class<X> type)

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