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.query.FromItem;
033: import com.caucho.amber.query.QueryParseException;
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.amber.type.Type;
038: import com.caucho.util.CharBuffer;
039:
040: /**
041: * Bound identifier expression.
042: */
043: public class ColumnExpr 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 ColumnExpr(PathExpr parent, Column column) {
054: _parent = parent;
055: _column = column;
056: }
057:
058: /**
059: * Returns the parent.
060: */
061: public PathExpr getParent() {
062: return _parent;
063: }
064:
065: /**
066: * Returns the name.
067: */
068: public Column getColumn() {
069: return _column;
070: }
071:
072: /**
073: * Returns the expr type.
074: */
075: public Type getType() {
076: return getColumn().getType();
077: }
078:
079: /**
080: * Returns true if this expr has any relationship.
081: */
082: public boolean hasRelationship() {
083: // jpa/1232
084: return !(_parent instanceof IdExpr);
085: }
086:
087: /**
088: * Returns a boolean expression.
089: */
090: public AmberExpr createBoolean() throws QueryParseException {
091: if (getColumn().getType().isBoolean())
092: return new BooleanColumnExpr(_parent, _column);
093: else
094: return super .createBoolean();
095: }
096:
097: /**
098: * Binds the expression as a select item.
099: */
100: public AmberExpr bindSelect(QueryParser parser) {
101: FromItem parentFromItem = _parent.bindSubPath(parser);
102:
103: if (parentFromItem.getTable() == getColumn().getTable()) {
104: _fromItem = parentFromItem;
105:
106: return this ;
107: }
108:
109: LinkColumns link = getColumn().getTable().getDependentIdLink();
110:
111: if (link == null)
112: return this ;
113:
114: _fromItem = parser
115: .createDependentFromItem(parentFromItem, link);
116:
117: return this ;
118: }
119:
120: /**
121: * Returns true if the expression uses the from item.
122: */
123: public boolean usesFrom(FromItem from, int type, boolean isNot) {
124: if (from.isOuterJoin() && type == AmberExpr.IS_INNER_JOIN) {
125: // jpa/115a
126: return false;
127: }
128:
129: if (_fromItem == from)
130: return true;
131: else if (_fromItem == null
132: && _parent.getChildFromItem() == from)
133: return true;
134: else
135: return false;
136: }
137:
138: /**
139: * Replaces linked join to eliminate a table.
140: */
141: public AmberExpr replaceJoin(JoinExpr join) {
142: _parent = (PathExpr) _parent.replaceJoin(join);
143:
144: return this ;
145: }
146:
147: /**
148: * Generates the where expression.
149: */
150: public void generateWhere(CharBuffer cb) {
151: generateInternalWhere(cb, true);
152: }
153:
154: /**
155: * Generates the (update) where expression.
156: */
157: public void generateUpdateWhere(CharBuffer cb) {
158: generateInternalWhere(cb, false);
159: }
160:
161: /**
162: * Generates the having expression.
163: */
164: public void generateHaving(CharBuffer cb) {
165: generateWhere(cb);
166: }
167:
168: public String toString() {
169: return _parent + "." + _column.getName();
170: }
171:
172: //
173: // private
174:
175: private void generateInternalWhere(CharBuffer cb, boolean select) {
176: if (_fromItem != null) {
177:
178: if (select) {
179: cb.append(_fromItem.getName());
180: cb.append('.');
181: }
182:
183: cb.append(_column.getName());
184: } else {
185:
186: if (select) {
187: cb.append(_parent.getChildFromItem().getName());
188: cb.append('.');
189: }
190:
191: cb.append(_column.getName());
192: }
193: }
194: }
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