Package adql.query.constraint

Class Exists

java.lang.Object
adql.query.constraint.Exists
All Implemented Interfaces:
ADQLObject, ADQLConstraint
public class Exists extends 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 Details

    • Exists

      public Exists(ADQLQuery query)
      Builds an Exists constraint instance.
      Parameters:
      query - Its sub-query.

    • Exists

      public Exists(Exists toCopy) throws Exception
      Builds an Exists constraint by copying the given one.
      Parameters:
      toCopy - The Exists constraint to copy.
      Throws:
      Exception - If there is an error during the copy.

  • Method Details

    • getSubQuery

      public final ADQLQuery getSubQuery()
      Gets the sub-query of this EXISTS constraint.
      Returns:
      Its sub-query.

    • setSubQuery

      public void setSubQuery(ADQLQuery query) throws NullPointerException
      Replaces the sub-query of this EXISTS constraint by the given one.
      Parameters:
      query - Its new sub-query.
      Throws:
      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 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:
      Exception - If there is any error during the copy.

    • getName

      public 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:

    • toADQL

      public 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.