01: /*
02: * Copyright (c) 1998 - 2005 Versant Corporation
03: * All rights reserved. This program and the accompanying materials
04: * are made available under the terms of the Eclipse Public License v1.0
05: * which accompanies this distribution, and is available at
06: * http://www.eclipse.org/legal/epl-v10.html
07: *
08: * Contributors:
09: * Versant Corporation - initial API and implementation
10: */
11: package com.versant.core.jdbc.sql.exp;
12:
13: import com.versant.core.jdbc.sql.SqlDriver;
14:
15: /**
16: * An expression with no children.
17: */
18: public class LeafExp extends SqlExp {
19:
20: public LeafExp() {
21: }
22:
23: public SqlExp createInstance() {
24: return new LeafExp();
25: }
26:
27: /**
28: * Create an aliases for any subtables we may have.
29: */
30: public int createAlias(int index) {
31: return index;
32: }
33:
34: /**
35: * Normalize this node i.e. transform it into its simplist possible form.
36: * This will turn sub selects into joins and so on.
37: */
38: public SqlExp normalize(SqlDriver driver, SelectExp sel,
39: boolean convertExists) {
40: return null;
41: }
42:
43: }
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