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 Software Foundation, Inc.
023: * 59 Temple Place, Suite 330
024: * Boston, MA 02111-1307 USA
025: *
026: * @author Scott Ferguson
027: */
028:
029: package com.caucho.amber.expr.fun;
030:
031: import com.caucho.amber.expr.AmberExpr;
032: import com.caucho.amber.query.QueryParser;
033: import com.caucho.util.CharBuffer;
034: import com.caucho.util.L10N;
035:
036: import java.util.ArrayList;
037:
038: /**
039: * SUBSTRING function expression
040: */
041: public class SubstringFunExpr extends FunExpr {
042: private static final L10N L = new L10N(SubstringFunExpr.class);
043:
044: /**
045: * Creates a new expression
046: */
047: protected SubstringFunExpr(QueryParser parser,
048: ArrayList<AmberExpr> args) {
049: super (parser, "substring", args, false);
050: }
051:
052: public static FunExpr create(QueryParser parser,
053: ArrayList<AmberExpr> args) {
054: return new SubstringFunExpr(parser, args);
055: }
056:
057: /**
058: * Generates the where expression.
059: */
060: public void generateWhere(CharBuffer cb) {
061: generateInternalWhere(cb, true);
062: }
063:
064: /**
065: * Generates the (update) where expression.
066: */
067: public void generateUpdateWhere(CharBuffer cb) {
068: generateInternalWhere(cb, false);
069: }
070:
071: //
072: // private/protected
073:
074: void generateInternalWhere(CharBuffer cb, boolean select) {
075: ArrayList<AmberExpr> args = getArgs();
076:
077: int n = args.size();
078:
079: // XXX: this validation should be moved to QueryParser
080: // if (n != 3)
081: // throw new QueryParseException(L.l("expected 3 arguments for SUBSTRING"));
082:
083: // XXX: MySQL requires 'substring' but Derby requires 'substr' and
084: // Postgres accepts both.
085: cb.append("substr(");
086:
087: if (select)
088: args.get(0).generateWhere(cb);
089: else
090: args.get(0).generateUpdateWhere(cb);
091:
092: cb.append(", ");
093:
094: if (select)
095: args.get(1).generateWhere(cb);
096: else
097: args.get(1).generateUpdateWhere(cb);
098:
099: cb.append(", ");
100:
101: if (select)
102: args.get(2).generateWhere(cb);
103: else
104: args.get(2).generateUpdateWhere(cb);
105:
106: cb.append(")");
107: }
108: }
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