Package adql.query.constraint

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

    • 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.

      • 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.