Package org.apache.openjpa.persistence.query

Class IsEmptyExpression

java.lang.Object

org.apache.openjpa.persistence.query.IsEmptyExpression

All Implemented Interfaces:

Serializable, Predicate, Visitable

public class IsEmptyExpression
extends Object

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected final Expression	_e
protected final UnaryConditionalOperator	_op
static final String	CLOSE_BRACE
static final String	COMMA
static final String	EMPTY
static final String	OPEN_BRACE
static final String	SPACE

Constructor Summary

Constructors

Constructor	Description
IsEmptyExpression(Expression op)

Method Summary

Modifier and Type	Method	Description
Predicate	and(Predicate predicate)	Creates an AND of the predicate with the argument.
String	asExpression(org.apache.openjpa.persistence.query.AliasContext ctx)	Get a JPQL fragment as used in WHERE clause.
String	asJoinable(org.apache.openjpa.persistence.query.AliasContext ctx)	Gets the string representation in FROM clause.
String	asProjection(org.apache.openjpa.persistence.query.AliasContext ctx)	Gets the string representation in SELECT projection.
String	getAliasHint(org.apache.openjpa.persistence.query.AliasContext ctx)	Gets the hint to be used while creating alias.
Expression	getOperand()
UnaryConditionalOperator	getOperator()
Predicate	not()	Creates a negation of the predicate with the argument.
Predicate	or(Predicate predicate)	Creates an OR of the predicate with the argument.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.openjpa.persistence.query.Visitable

asJoinable, asProjection, getAliasHint

Field Details

_e

protected final Expression _e

_op

protected final UnaryConditionalOperator _op

SPACE

public static final String SPACE

See Also:

• Constant Field Values

OPEN_BRACE

public static final String OPEN_BRACE

See Also:

• Constant Field Values

CLOSE_BRACE

public static final String CLOSE_BRACE

See Also:

• Constant Field Values

COMMA

public static final String COMMA

See Also:

• Constant Field Values

EMPTY

public static final String EMPTY

See Also:

• Constant Field Values

Constructor Details

IsEmptyExpression

public IsEmptyExpression(Expression op)

Method Details

asExpression

public String asExpression(org.apache.openjpa.persistence.query.AliasContext ctx)

Description copied from interface: Visitable

Get a JPQL fragment as used in WHERE clause.

Specified by:

asExpression in interface Visitable

getOperand

public Expression getOperand()

getOperator

public UnaryConditionalOperator getOperator()

and

public Predicate and(Predicate predicate)

Description copied from interface: Predicate

Creates an AND of the predicate with the argument.

Specified by:

and in interface Predicate

Parameters:

predicate - - A simple or compound predicate

Returns:

the predicate that is the AND of the original simple or compound predicate and the argument.

or

public Predicate or(Predicate predicate)

Description copied from interface: Predicate

Creates an OR of the predicate with the argument.

Specified by:

or in interface Predicate

Parameters:

predicate - - A simple or compound predicate

Returns:

the predicate that is the OR of the original simple or compound predicate and the argument.

not

public Predicate not()

Description copied from interface: Predicate

Creates a negation of the predicate with the argument.

Specified by:

not in interface Predicate

Returns:

the predicate that is the negation of the original simple or compound predicate.

asProjection

public String asProjection(org.apache.openjpa.persistence.query.AliasContext ctx)

Description copied from interface: Visitable

Gets the string representation in SELECT projection.

Specified by:

asProjection in interface Visitable

getAliasHint

public String getAliasHint(org.apache.openjpa.persistence.query.AliasContext ctx)

Description copied from interface: Visitable

Gets the hint to be used while creating alias.

Specified by:

getAliasHint in interface Visitable

asJoinable

public String asJoinable(org.apache.openjpa.persistence.query.AliasContext ctx)

Description copied from interface: Visitable

Gets the string representation in FROM clause.

Specified by:

asJoinable in interface Visitable