package adql.query;
/*
* This file is part of ADQLLibrary.
*
* ADQLLibrary is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* ADQLLibrary is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with ADQLLibrary. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2012 - UDS/Centre de Données astronomiques de Strasbourg (CDS)
*/
/**
* Represents an item of the ORDER BY list: that's to say a column reference plus a sorting indication (ASC, DESC).
*
* @author Grégory Mantelet (CDS)
* @version 06/2011
*/
public class ADQLOrder extends ColumnReference {
/** Gives an indication about how to order the results of a query. (<i>true</i> for DESCending, <i>false</i> for ASCending) */
private boolean descSorting = false;
/**
* Builds an order indication with the index of the selected column on which an ASCending ordering will be done.
*
* @param colIndex The index of a selected column (from 1).
*
* @throws ArrayIndexOutOfBoundsException If the index is less or equal 0.
*
* @see ADQLOrder#ADQLOrder(int, boolean)
*/
public ADQLOrder(int colIndex) throws ArrayIndexOutOfBoundsException{
this(colIndex, false);
}
/**
* Builds an order indication with the index of the selected column on which the specified ordering will be done.
*
* @param colIndex The index of a selected column (from 1).
* @param desc <i>true</i> means DESCending order, <i>false</i> means ASCending order.
*
* @throws ArrayIndexOutOfBoundsException If the index is less or equal 0.
*/
public ADQLOrder(int colIndex, boolean desc) throws ArrayIndexOutOfBoundsException{
super(colIndex);
descSorting = desc;
}
/**
* Builds an order indication with the name or the alias of the selected column on which an ASCending ordering will be done.
*
* @param colName The name or the alias of a selected column.
*
* @throws NullPointerException If the given name is <i>null</i> or is an empty string.
*
* @see ADQLOrder#ADQLOrder(String, boolean)
*/
public ADQLOrder(String colName) throws NullPointerException{
this(colName, false);
}
/**
* Builds an order indication with the name of the alias of the selected column on which the specified ordering will be done.
*
* @param colName The name of the alias of a selected column.
* @param desc <i>true</i> means DESCending order, <i>false</i> means ASCending order.
*
* @throws NullPointerException If the given name is <i>null</i> or is an empty string.
*/
public ADQLOrder(String colName, boolean desc) throws NullPointerException{
super(colName);
descSorting = desc;
}
/**
* Builds an ORDER BY item by copying the given one.
*
* @param toCopy The ORDER BY item to copy.
*/
public ADQLOrder(ADQLOrder toCopy){
super(toCopy);
descSorting = toCopy.descSorting;
}
/**
* Tells how the results will be sorted.
*
* @return <i>true</i> DESCending order, <i>false</i> ASCending order.
*/
public boolean isDescSorting(){
return descSorting;
}
/**
* Updates the current order indication.
*
* @param colIndex The index of a selected column (from 1).
* @param desc <i>true</i> means DESCending order, <i>false</i> means ASCending order.
*
* @throws IndexOutOfBoundsException If the given index is less or equal 0.
*/
public void setOrder(int colIndex, boolean desc) throws ArrayIndexOutOfBoundsException{
if (colIndex <= 0)
throw new ArrayIndexOutOfBoundsException("Impossible to make a reference to the " + colIndex + "th column: a column index must be greater or equal 1 !");
setColumnIndex(colIndex);
descSorting = desc;
}
/**
* Updates the current order indication.
*
* @param colName The name or the alias of a selected column.
* @param desc <i>true</i> means DESCending order, <i>false</i> means ASCending order.
*
* @throws NullPointerException If the given name is <i>null</i> or is an empty string.
*/
public void setOrder(String colName, boolean desc) throws NullPointerException{
if (colName == null)
throw new NullPointerException("Impossible to make a reference: the given name is null or is an empty string !");
setColumnName(colName);
descSorting = desc;
}
@Override
public ADQLObject getCopy() throws Exception{
return new ADQLOrder(this);
}
@Override
public String getName(){
return super.getName() + (descSorting ? " DESC" : " ASC");
}
@Override
public String toADQL(){
return super.toADQL() + (descSorting ? " DESC" : " ASC");
}
}