001: /*
002: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
003: *
004: * This file is part of Resin(R) Open Source
005: *
006: * Each copy or derived work must preserve the copyright notice and this
007: * notice unmodified.
008: *
009: * Resin Open Source is free software; you can redistribute it and/or modify
010: * it under the terms of the GNU General Public License as published by
011: * the Free Software Foundation; either version 2 of the License, or
012: * (at your option) any later version.
013: *
014: * Resin Open Source is distributed in the hope that it will be useful,
015: * but WITHOUT ANY WARRANTY; without even the implied warranty of
016: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
017: * of NON-INFRINGEMENT. See the GNU General Public License for more
018: * details.
019: *
020: * You should have received a copy of the GNU General Public License
021: * along with Resin Open Source; if not, write to the
022: * Free SoftwareFoundation, Inc.
023: * 59 Temple Place, Suite 330
024: * Boston, MA 02111-1307 USA
025: *
026: * @author Scott Ferguson
027: */
028:
029: package com.caucho.db.sql;
030:
031: import com.caucho.log.Log;
032:
033: import java.sql.SQLException;
034: import java.util.ArrayList;
035: import java.util.logging.Logger;
036:
037: class NotExpr extends Expr {
038: private static final Logger log = Log.open(NotExpr.class);
039:
040: private Expr _sub;
041:
042: NotExpr(Expr sub) {
043: _sub = sub;
044: }
045:
046: /**
047: * Binds the expression to the actual tables.
048: */
049: protected Expr bind(Query query) throws SQLException {
050: _sub = _sub.bind(query);
051:
052: if (!_sub.isBoolean())
053: throw new SQLException(L
054: .l("NOT requires a boolean expression"));
055:
056: return this ;
057: }
058:
059: /**
060: * Returns the type of the expression.
061: */
062: public Class getType() {
063: return boolean.class;
064: }
065:
066: /**
067: * Returns the cost based on the given FromList.
068: */
069: public long subCost(ArrayList<FromItem> fromList) {
070: return _sub.subCost(fromList);
071: }
072:
073: /**
074: * Evaluates the expression for nulls
075: */
076: public boolean isNull(QueryContext context) throws SQLException {
077: return _sub.isNull(context);
078: }
079:
080: /**
081: * Evaluates the expression as a boolean
082: *
083: * @param rows the current tuple being evaluated
084: *
085: * @return the boolean value
086: */
087: public int evalBoolean(QueryContext context) throws SQLException {
088: int value = _sub.evalBoolean(context);
089:
090: switch (value) {
091: case TRUE:
092: return FALSE;
093: case FALSE:
094: return TRUE;
095: default:
096: return UNKNOWN;
097: }
098: }
099:
100: /**
101: * Evaluates the expression as a string.
102: *
103: * @param rows the current tuple being evaluated
104: *
105: * @return the string value
106: */
107: public String evalString(QueryContext context) throws SQLException {
108: int value = _sub.evalBoolean(context);
109:
110: switch (value) {
111: case TRUE:
112: return "1";
113: case FALSE:
114: return "0";
115: default:
116: return null;
117: }
118: }
119:
120: /**
121: * Evaluates aggregate functions during the group phase.
122: *
123: * @param state the current database tuple
124: */
125: public void evalGroup(QueryContext context) throws SQLException {
126: _sub.evalGroup(context);
127: }
128:
129: public String toString() {
130: return "NOT " + _sub;
131: }
132: }
|