001: /*
002: * $Id: AmbiguousColumnReferenceVisitor.java,v 1.2 2005/12/20 18:32:27 ahimanikya Exp $
003: * =======================================================================
004: * Copyright (c) 2004 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: package org.axiondb.engine.visitors;
041:
042: import java.util.HashSet;
043: import java.util.List;
044: import java.util.Set;
045:
046: import org.axiondb.AxionException;
047: import org.axiondb.ColumnIdentifier;
048: import org.axiondb.Literal;
049: import org.axiondb.OrderNode;
050: import org.axiondb.engine.commands.SubSelectCommand;
051: import org.axiondb.functions.ConcreteFunction;
052:
053: /**
054: * Assert Ambiguous Column Reference.
055: *
056: * @author Ahimanikya Satapathy
057: */
058: public class AmbiguousColumnReferenceVisitor {
059:
060: public void visit(List selectList, List referenceColumns)
061: throws AxionException {
062: for (int i = 0, I = referenceColumns.size(); i < I; i++) {
063: String refCol = getResolvedColumnName(referenceColumns
064: .get(i));
065: Set colidset = new HashSet();
066: for (int j = 0, J = selectList.size(); j < J; j++) {
067: Object col = selectList.get(j);
068: String colname = getResolvedColumnName(col);
069:
070: if (colidset.contains(colname)
071: && !(col instanceof Literal)) {
072: throw new AxionException(42705);
073: }
074: if (refCol.equals(colname)) {
075: colidset.add(colname);
076: }
077: }
078: }
079: }
080:
081: private String getResolvedColumnName(Object obj) {
082: String colName = null;
083: if (obj instanceof ColumnIdentifier) {
084: ColumnIdentifier col = (ColumnIdentifier) obj;
085: colName = col.getAlias();
086: if (colName == null) {
087: colName = col.getName();
088: }
089: } else if (obj instanceof ConcreteFunction) {
090: ConcreteFunction fn = (ConcreteFunction) obj;
091: colName = fn.getLabel();
092: } else if (obj instanceof SubSelectCommand) {
093: SubSelectCommand sq = (SubSelectCommand) obj;
094: colName = sq.getName();
095: } else if (obj instanceof Literal) {
096: Literal lit = (Literal) obj;
097: colName = lit.getName();
098: } else if (obj instanceof OrderNode) {
099: colName = getResolvedColumnName(((OrderNode) obj)
100: .getSelectable());
101: }
102: return colName;
103: }
104:
105: }
|