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: *
023: * Free Software Foundation, Inc.
024: * 59 Temple Place, Suite 330
025: * Boston, MA 02111-1307 USA
026: *
027: * @author Scott Ferguson
028: */
029:
030: package com.caucho.amber.expr;
031:
032: import com.caucho.amber.manager.AmberPersistenceUnit;
033: import com.caucho.amber.query.FromItem;
034: import com.caucho.amber.query.QueryParser;
035: import com.caucho.amber.table.Column;
036: import com.caucho.amber.table.LinkColumns;
037: import com.caucho.jdbc.JdbcMetaData;
038: import com.caucho.util.CharBuffer;
039:
040: /**
041: * Column expression returning a boolean
042: */
043: public class BooleanColumnExpr extends AbstractAmberExpr {
044: protected PathExpr _parent;
045: // identifier name value
046: private Column _column;
047:
048: protected FromItem _fromItem;
049:
050: /**
051: * Creates a new unbound id expression.
052: */
053: public BooleanColumnExpr(PathExpr parent, Column column) {
054: _parent = parent;
055: _column = column;
056: }
057:
058: /**
059: * Returns the parent.
060: */
061: PathExpr getParent() {
062: return _parent;
063: }
064:
065: /**
066: * Returns the name.
067: */
068: Column getColumn() {
069: return _column;
070: }
071:
072: /**
073: * Returns true for a boolean.
074: */
075: public boolean isBoolean() {
076: return true;
077: }
078:
079: /**
080: * Binds the expression as a select item.
081: */
082: public AmberExpr bindSelect(QueryParser parser) {
083: FromItem parentFromItem = _parent.bindSubPath(parser);
084:
085: if (parentFromItem.getTable() == getColumn().getTable()) {
086: _fromItem = parentFromItem;
087:
088: return this ;
089: }
090:
091: LinkColumns link = getColumn().getTable().getDependentIdLink();
092: _fromItem = parser
093: .createDependentFromItem(parentFromItem, link);
094:
095: return this ;
096: }
097:
098: /**
099: * Returns true if the expression uses the from item.
100: */
101: public boolean usesFrom(FromItem from, int type, boolean isNot) {
102: if (_fromItem == from)
103: return true;
104: else if (_fromItem == null
105: && _parent.getChildFromItem() == from)
106: return true;
107: else
108: return false;
109: }
110:
111: /**
112: * Replaces linked join to eliminate a table.
113: */
114: public AmberExpr replaceJoin(JoinExpr join) {
115: _parent = (PathExpr) _parent.replaceJoin(join);
116:
117: return this ;
118: }
119:
120: /**
121: * Generates the where expression.
122: */
123: public void generateWhere(CharBuffer cb) {
124: generateInternalWhere(cb, true);
125: }
126:
127: /**
128: * Generates the (update) where expression.
129: */
130: public void generateUpdateWhere(CharBuffer cb) {
131: generateInternalWhere(cb, false);
132: }
133:
134: /**
135: * Generates the having expression.
136: */
137: public void generateHaving(CharBuffer cb) {
138: generateWhere(cb);
139: }
140:
141: public String toString() {
142: return _parent + "." + _column.getName();
143: }
144:
145: //
146: // private
147:
148: private void generateInternalWhere(CharBuffer cb, boolean select) {
149: CharBuffer term = new CharBuffer();
150:
151: if (_fromItem != null) {
152:
153: if (select) {
154: term.append(_fromItem.getName());
155: term.append('.');
156: }
157:
158: term.append(_column.getName());
159: } else {
160:
161: if (select) {
162: term.append(_parent.getChildFromItem().getName());
163: term.append('.');
164: }
165:
166: term.append(_column.getName());
167: }
168:
169: AmberPersistenceUnit manager = _column.getTable()
170: .getAmberManager();
171:
172: JdbcMetaData metaData = manager.getMetaData();
173:
174: cb.append(metaData.generateBoolean(term.toString()));
175: }
176: }
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