expressionfunctionabs.java

java 数据库 功能强大 效率高 SmallSQL Database is a free DBMS library for the Java(tm) platform. It runs on

/* =============================================================
 * SmallSQL : a free Java DBMS library for the Java(tm) platform
 * =============================================================
 *
 * (C) Copyright 2004-2006, by Volker Berlin.
 *
 * Project Info:  http://www.smallsql.de/
 *
 * 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.]
 *
 * ---------------
 * ExpressionFunctionAbs.java
 * ---------------
 * Author: Volker Berlin
 * 
 */
package smallsql.database;


class ExpressionFunctionAbs extends ExpressionFunctionReturnP1 {

    int getFunction(){ return SQLTokenizer.ABS; }


	boolean getBoolean() throws Exception{
        return getDouble() != 0;
    }

    int getInt() throws Exception{
        return Math.abs( param1.getInt() );
    }

    long getLong() throws Exception{
        return Math.abs( param1.getLong() );
    }

    float getFloat() throws Exception{
        return Math.abs( param1.getFloat() );
    }

    double getDouble() throws Exception{
        return Math.abs( param1.getDouble() );
    }

    long getMoney() throws Exception{
        return Math.abs( param1.getMoney() );
    }

    MutableNumeric getNumeric() throws Exception{
		if(param1.isNull()) return null;
        MutableNumeric num = param1.getNumeric();
        if(num.getSignum() < 0) num.setSignum(1);
        return num;
    }

    Object getObject() throws Exception{
		if(param1.isNull()) return null;
        Object para1 = param1.getObject();
        switch(param1.getDataType()){
        case SQLTokenizer.FLOAT:
        case SQLTokenizer.DOUBLE:
            double dValue = ((Double)para1).doubleValue();
            return (dValue<0) ? new Double(-dValue) : para1;
        case SQLTokenizer.REAL:
            double fValue = ((Float)para1).floatValue();
            return (fValue<0) ? new Float(-fValue) : para1;
        case SQLTokenizer.BIGINT:
            long lValue = ((Number)para1).longValue();
            return (lValue<0) ? new Long(-lValue) : para1;
        case SQLTokenizer.TINYINT:
        case SQLTokenizer.SMALLINT:
        case SQLTokenizer.INT:
            int iValue = ((Number)para1).intValue();
            return (iValue<0) ? new Integer(-iValue) : para1;
        case SQLTokenizer.NUMERIC:
        case SQLTokenizer.DECIMAL:
            MutableNumeric nValue = (MutableNumeric)para1;
            if(nValue.getSignum() <0) nValue.setSignum(1);
            return nValue;
        case SQLTokenizer.MONEY:
            Money mValue = (Money)para1;
            if(mValue.value <0) mValue.value = -mValue.value;
            return mValue;
        default: throw createUnspportedDataType(param1.getDataType());
        }
    }

    String getString() throws Exception{
        Object obj = getObject();
        if(obj == null) return null;
        return obj.toString();
    }
    

}