adql.query.constraint

Class Exists

java.lang.Object

adql.query.constraint.Exists

All Implemented Interfaces:

ADQLObject, ADQLConstraint

public class Exists
extends java.lang.Object
implements ADQLConstraint

Represents the predicate EXISTS of SQL and ADQL.

This function returns true if the sub-query given in parameter returns at least one result, else it returns false.

Version:

1.4 (06/2015)

Author:

Grégory Mantelet (CDS;ARI)

Constructor Summary

Constructors

Constructor and Description
Exists(ADQLQuery query) Builds an Exists constraint instance.
Exists(Exists toCopy) Builds an Exists constraint by copying the given one.

Method Summary

Modifier and Type	Method and Description
ADQLIterator	adqlIterator() Gets an iterator on the intern ADQL objects.
ADQLObject	getCopy() Gets a (deep) copy of this ADQL object.
java.lang.String	getName() Gets the name of this object in ADQL.
TextPosition	getPosition() Gets the position of this object/token in the ADQL query.
ADQLQuery	getSubQuery() Gets the sub-query of this EXISTS constraint.
void	setPosition(TextPosition position) Set the position of this Exists in the given ADQL query string.
void	setSubQuery(ADQLQuery query) Replaces the sub-query of this EXISTS constraint by the given one.
java.lang.String	toADQL() Gets the ADQL expression of this object.

Methods inherited from class java.lang.Object

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

Constructor Detail

Exists

public Exists(ADQLQuery query)

Builds an Exists constraint instance.

Parameters:

query - Its sub-query.

Exists

public Exists(Exists toCopy)
       throws java.lang.Exception

Builds an Exists constraint by copying the given one.

Parameters:

toCopy - The Exists constraint to copy.

Throws:

java.lang.Exception - If there is an error during the copy.

Method Detail

getSubQuery

public final ADQLQuery getSubQuery()

Gets the sub-query of this EXISTS constraint.

Returns:

Its sub-query.

setSubQuery

public void setSubQuery(ADQLQuery query)
                 throws java.lang.NullPointerException

Replaces the sub-query of this EXISTS constraint by the given one.

Parameters:

query - Its new sub-query.

Throws:

java.lang.NullPointerException - If the given query is null.

getPosition

public final TextPosition getPosition()

Description copied from interface: ADQLObject

Gets the position of this object/token in the ADQL query.

By default, no position should be set.

Specified by:

getPosition in interface ADQLObject

Returns:

Position of this ADQL item in the ADQL query, or NULL if not written originally in the query (for example, if added afterwards.

setPosition

public final void setPosition(TextPosition position)

Set the position of this Exists in the given ADQL query string.

Parameters:

position - New position of this Exists.

Since:

1.4

getCopy

public ADQLObject getCopy()
                   throws java.lang.Exception

Description copied from interface: ADQLObject

Gets a (deep) copy of this ADQL object.

Specified by:

getCopy in interface ADQLObject

Returns:

The copy of this ADQL object.

Throws:

java.lang.Exception - If there is any error during the copy.

getName

public java.lang.String getName()

Description copied from interface: ADQLObject

Gets the name of this object in ADQL.

Specified by:

getName in interface ADQLObject

Returns:

The name of this ADQL object.

adqlIterator

public ADQLIterator adqlIterator()

Description copied from interface: ADQLObject

Gets an iterator on the intern ADQL objects.

Note:The returned iterator is particularly used by a ISearchHandler extension to browse a whole ADQL tree.

Specified by:

adqlIterator in interface ADQLObject

Returns:

An ADQL objects iterator.

See Also:

ADQLIterator, ISearchHandler

toADQL

public java.lang.String toADQL()

Description copied from interface: ADQLObject

Gets the ADQL expression of this object.

Specified by:

toADQL in interface ADQLObject

Returns:

The corresponding ADQL expression.