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: * CONCAT function expression
040: */
041: public class ConcatFunExpr extends FunExpr {
042: private static final L10N L = new L10N(ConcatFunExpr.class);
043:
044: /**
045: * Creates a new expression
046: */
047: protected ConcatFunExpr(QueryParser parser,
048: ArrayList<AmberExpr> args) {
049: super (parser, "concat", args, false);
050: }
051:
052: public static FunExpr create(QueryParser parser,
053: ArrayList<AmberExpr> args) {
054: return new ConcatFunExpr(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 != 2)
081: // throw new QueryParseException(L.l("expected 2 string arguments for CONCAT"));
082:
083: if (_parser.isDerbyDBMS()) {
084:
085: // Derby does not accept two params in (? || ?).
086: // Translates to ((? || '') || ('' || ?)).
087:
088: // XXX: there seems to be an issue with VARCHAR(32672)
089: // and a Derby driver patch should be released soon.
090:
091: cb.append("VARCHAR(CAST(");
092:
093: if (select)
094: args.get(0).generateWhere(cb);
095: else
096: args.get(0).generateUpdateWhere(cb);
097:
098: cb.append("AS VARCHAR(2000)) || CAST(");
099:
100: if (select)
101: args.get(1).generateWhere(cb);
102: else
103: args.get(1).generateUpdateWhere(cb);
104:
105: cb.append(" AS VARCHAR(2000)))");
106:
107: return;
108: } else if (_parser.isPostgresDBMS()) {
109: // jpa/1230
110: generateInternalConcat(cb, true, true, null, select);
111: return;
112: }
113:
114: cb.append("concat");
115:
116: generateInternalConcat(cb, true, true, null, select);
117: }
118:
119: private void generateInternalConcat(CharBuffer cb, boolean arg0,
120: boolean arg1, String str, boolean select) {
121: ArrayList<AmberExpr> args = getArgs();
122:
123: boolean usesConcatOperator = _parser.isDerbyDBMS()
124: || _parser.isPostgresDBMS();
125:
126: cb.append('(');
127:
128: if (arg0) {
129: if (select)
130: args.get(0).generateWhere(cb);
131: else
132: args.get(0).generateUpdateWhere(cb);
133:
134: if (usesConcatOperator)
135: cb.append(" || ");
136: else
137: cb.append(',');
138: }
139:
140: if (arg1) {
141: if (select)
142: args.get(1).generateWhere(cb);
143: else
144: args.get(1).generateUpdateWhere(cb);
145:
146: if (arg0) {
147: cb.append(')');
148: return;
149: }
150:
151: if (usesConcatOperator)
152: cb.append(" || ");
153: else
154: cb.append(',');
155: }
156:
157: cb.append('\'');
158:
159: cb.append(str);
160:
161: cb.append('\'');
162:
163: cb.append(')');
164: }
165: }
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