*
* This library 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 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ---------------
* ExpressionFunctionRand.java
* ---------------
* Author: Volker Berlin
*
*/
package smallsql.database;
import java.util.Random;
final class ExpressionFunctionRand extends ExpressionFunctionReturnFloat {
final static private Random random = new Random();
final int getFunction(){ return SQLTokenizer.RAND; }
boolean isNull() throws Exception{
return getParams().length == 1 && param1.isNull();
}
final double getDouble() throws Exception{
if(getParams().length == 0)
return random.nextDouble();
if(isNull()) return 0;
return new Random(param1.getLong()).nextDouble();
}
}