001: /*
002: * $Id: DateToCharFunction.java,v 1.8 2005/05/02 22:28:41 ahimanikya Exp $
003: * =======================================================================
004: * Copyright (c) 2002-2005 Axion Development Team. All rights reserved.
005: *
006: * Redistribution and use in source and binary forms, with or without
007: * modification, are permitted provided that the following conditions
008: * are met:
009: *
010: * 1. Redistributions of source code must retain the above
011: * copyright notice, this list of conditions and the following
012: * disclaimer.
013: *
014: * 2. Redistributions in binary form must reproduce the above copyright
015: * notice, this list of conditions and the following disclaimer in
016: * the documentation and/or other materials provided with the
017: * distribution.
018: *
019: * 3. The names "Tigris", "Axion", nor the names of its contributors may
020: * not be used to endorse or promote products derived from this
021: * software without specific prior written permission.
022: *
023: * 4. Products derived from this software may not be called "Axion", nor
024: * may "Tigris" or "Axion" appear in their names without specific prior
025: * written permission.
026: *
027: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
028: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
029: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
030: * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
031: * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
032: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
033: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
034: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
035: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
036: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
037: * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
038: * =======================================================================
039: */
040:
041: package org.axiondb.functions;
042:
043: import java.sql.Timestamp;
044:
045: import org.axiondb.AxionException;
046: import org.axiondb.DataType;
047: import org.axiondb.FunctionFactory;
048: import org.axiondb.RowDecorator;
049: import org.axiondb.types.StringType;
050: import org.axiondb.types.TimestampType;
051: import org.axiondb.util.DateTimeUtils;
052:
053: /**
054: * Syntax: DateToChar( date-expr, 'format-string' )
055: *
056: * @version $Revision: 1.8 $ $Date: 2005/05/02 22:28:41 $
057: * @author Jonathan Giron
058: */
059: public class DateToCharFunction extends BaseFunction implements
060: ScalarFunction, FunctionFactory {
061:
062: /** Creates a new instance of Class */
063: public DateToCharFunction() {
064: super ("DATETOCHAR");
065: }
066:
067: public ConcreteFunction makeNewInstance() {
068: return new DateToCharFunction();
069: }
070:
071: /** {@link DataType} */
072: public DataType getDataType() {
073: return RETURN_TYPE;
074: }
075:
076: /**
077: * Returns String value representing the timestamp/date value in the given format.
078: *
079: * @param row
080: * @return String representation of the timestamp/date value
081: */
082: public Object evaluate(RowDecorator row) throws AxionException {
083: Timestamp timestamp = null;
084: String formatStr = null;
085:
086: // Get 'format-literal'
087: Object arg2 = getArgument(1).evaluate(row);
088: if (null == arg2) {
089: throw new AxionException(
090: "DateToChar cannot accept a null format string.");
091: } else {
092: formatStr = (String) ARG2_TYPE.convert(arg2);
093: }
094:
095: // Get 'date-expr'
096: Object arg1 = getArgument(0).evaluate(row);
097: if (null == arg1) {
098: return null;
099: } else {
100: timestamp = (Timestamp) ARG1_TYPE.convert(arg1);
101: }
102:
103: return DateTimeUtils.convertToChar(timestamp, formatStr);
104: }
105:
106: public boolean isValid() {
107: return (getArgumentCount() >= 2);
108: }
109:
110: private static final DataType RETURN_TYPE = new StringType();
111: private static final DataType ARG1_TYPE = new TimestampType();
112: private static final DataType ARG2_TYPE = new StringType();
113: }
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