Interface Expression<T>

Type Parameters:

T - the type of the expression

All Superinterfaces:

Selection<T>, TupleElement<T>

All Known Subinterfaces:

BooleanExpression, BooleanPath, CollectionJoin<Z,E>, ComparableExpression<C>, 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>, NumericExpression<N>, ParameterExpression<T>, Path<X>, PluralExpression<C,E>, PluralJoin<Z,C,E>, Predicate, Root<X>, SetJoin<Z,E>, Subquery<T>, TemporalExpression<T>, TextExpression

public interface Expression<T>
extends Selection<T>

Type for query expressions.

Since:

2.0

Method Summary

Modifier and Type	Method	Description
<X> Expression<X>	as(Class<X> type)	Perform a typecast upon the expression, returning a new expression object.
<X> Expression<X>	cast(Class<X> type)	Cast this expression to the specified type, returning a new expression object.
Expression<T>	coalesce(Expression<? extends T> y)	Create an expression that returns null if this and the argument evaluate to null, and the value of the first non-null expression otherwise.
Expression<T>	coalesce(T y)	Create an expression that returns null if this and the argument evaluate to null, and the value of the first non-null expression otherwise.
NumericExpression<Long>	count()	Create an aggregate expression applying the count operation.
NumericExpression<Long>	countDistinct()	Create an aggregate expression applying the count distinct operation.
Predicate	equalTo(Expression<?> value)	Create a predicate to test whether the expression is equal to the argument.
Predicate	equalTo(Object value)	Create a predicate to test whether the expression is equal to the argument.
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(Subquery<T> subquery)	Create a predicate to test whether the expression is returned by the subquery.
Predicate	in(Object... values)	Create a predicate to test whether the expression is a member of the argument list.
Predicate	in(Collection<?> values)	Create a predicate to test whether the expression is a member of the collection.
Predicate	isMember(Expression<? extends Collection<? super T>> collection)	Create a predicate that tests whether this expression is a member of a collection.
Predicate	isNotMember(Expression<? extends Collection<? super T>> collection)	Create a predicate that tests whether this expression is not a member of a collection.
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.
Predicate	notEqualTo(Expression<?> value)	Create a predicate to test whether the expression is unequal to the argument.
Predicate	notEqualTo(Object value)	Create a predicate to test whether the expression is unequal to the argument.
Expression<T>	nullif(Expression<? extends T> y)	Create an expression that tests whether this expression is equal to the argument, returning null if they are and the value of the first expression if they are not.
Expression<T>	nullif(T y)	Create an expression that tests whether this expression is equal to the argument, returning null if they are and the value of the first expression if they are not.
<R> CriteriaBuilder.SimpleCase<T,R>	selectCase(Class<R> type)	Create a simple case expression to test against this expression.

Methods inherited from interface Selection

alias, getCompoundSelectionItems, isCompoundSelection

Methods inherited from interface TupleElement

getAlias, getJavaType

Method Details

isNull

@Nonnull
Predicate isNull()

Create a predicate to test whether the expression is null.

Returns:

predicate testing whether the expression is null

isNotNull

@Nonnull
Predicate isNotNull()

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

Returns:

predicate testing whether the expression is not null

equalTo

@Nonnull
Predicate equalTo(@Nonnull
 Expression<?> value)

Create a predicate to test whether the expression is equal to the argument.

Parameters:

value - expression to be tested against

Returns:

predicate testing for equality

Since:

3.2

equalTo

@Nonnull
Predicate equalTo(Object value)

Create a predicate to test whether the expression is equal to the argument.

Parameters:

value - value to be tested against

Returns:

predicate testing for equality

Since:

3.2

notEqualTo

@Nonnull
Predicate notEqualTo(@Nonnull
 Expression<?> value)

Create a predicate to test whether the expression is unequal to the argument.

Parameters:

value - expression to be tested against

Returns:

predicate testing for inequality

Since:

3.2

notEqualTo

@Nonnull
Predicate notEqualTo(Object value)

Create a predicate to test whether the expression is unequal to the argument.

Parameters:

value - value to be tested against

Returns:

predicate testing for inequality

Since:

3.2

in

@Nonnull
Predicate in(@Nonnull
 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

@Nonnull
Predicate in(@Nonnull
 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

@Nonnull
Predicate in(@Nonnull
 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

@Nonnull
Predicate in(@Nonnull
 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

in

@Nonnull
Predicate in(@Nonnull
 Subquery<T> subquery)

Create a predicate to test whether the expression is returned by the subquery.

Parameters:

subquery - the subquery

Returns:

predicate testing for membership

Since:

4.0

as

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

Perform a typecast upon the expression, returning a new expression object. Unlike cast(Class), this method does not cause type conversion: the runtime type is not changed.

Warning: may result in a runtime failure.

Type Parameters:

X - the intended type of the expression

Parameters:

type - intended type of the expression

Returns:

new expression of the given type

See Also:

• cast(Class)

cast

@Nonnull
<X> Expression<X> cast(@Nonnull
 Class<X> type)

Cast this expression to the specified type, returning a new expression object. Unlike as(Class), this method does result in a runtime type conversion.

Providers are required to support casting scalar expressions to String, and String expressions to Integer, Long, Float, and Double. Support for typecasts between other basic types is not required.

Type Parameters:

X - the target type of the cast

Parameters:

type - a basic type

Returns:

a scalar expression of the given basic type

Since:

3.2

coalesce

@Nonnull
Expression<T> coalesce(@Nonnull
 Expression<? extends T> y)

Create an expression that returns null if this and the argument evaluate to null, and the value of the first non-null expression otherwise.

Parameters:

y - expression

Returns:

coalesce expression

Since:

4.0

coalesce

@Nonnull
Expression<T> coalesce(T y)

Create an expression that returns null if this and the argument evaluate to null, and the value of the first non-null expression otherwise.

Parameters:

y - value

Returns:

coalesce expression

Since:

4.0

nullif

@Nonnull
Expression<T> nullif(@Nonnull
 Expression<? extends T> y)

Create an expression that tests whether this expression is equal to the argument, returning null if they are and the value of the first expression if they are not.

Parameters:

y - expression

Returns:

nullif expression

Since:

4.0

nullif

@Nonnull
Expression<T> nullif(T y)

Create an expression that tests whether this expression is equal to the argument, returning null if they are and the value of the first expression if they are not.

Parameters:

y - value

Returns:

nullif expression

Since:

4.0

selectCase

@Nonnull
<R> CriteriaBuilder.SimpleCase<T,R> selectCase(@Nonnull
 Class<R> type)

Create a simple case expression to test against this expression.

Type Parameters:

R - the result type of the case expression

Parameters:

type - the type of the result of the case expression

Returns:

simple case expression

Since:

4.0

isMember

@Nonnull
Predicate isMember(@Nonnull
 Expression<? extends Collection<? super T>> collection)

Create a predicate that tests whether this expression is a member of a collection. If the collection is empty, the predicate will be false.

Parameters:

collection - expression

Returns:

is-member predicate

Since:

4.0

isNotMember

@Nonnull
Predicate isNotMember(@Nonnull
 Expression<? extends Collection<? super T>> collection)

Create a predicate that tests whether this expression is not a member of a collection. If the collection is empty, the predicate will be true.

Parameters:

collection - expression

Returns:

is-not-member predicate

Since:

4.0

count

@Nonnull
NumericExpression<Long> count()

Create an aggregate expression applying the count operation.

Returns:

count expression

Since:

4.0

countDistinct

@Nonnull
NumericExpression<Long> countDistinct()

Create an aggregate expression applying the count distinct operation.

Returns:

count distinct expression

Since:

4.0