01: /*
02: * Copyright Aduna (http://www.aduna-software.com/) (c) 2008.
03: *
04: * Licensed under the Aduna BSD-style license.
05: */
06: package org.openrdf.sail.rdbms.algebra;
07:
08: import org.openrdf.sail.rdbms.algebra.base.RdbmsQueryModelVisitorBase;
09: import org.openrdf.sail.rdbms.algebra.base.SqlConstant;
10:
11: /**
12: * The SQL NULL expression.
13: *
14: * @author James Leigh
15: *
16: */
17: public class SqlNull extends SqlConstant<Object> {
18:
19: public SqlNull() {
20: super (null);
21: }
22:
23: @Override
24: public <X extends Exception> void visit(
25: RdbmsQueryModelVisitorBase<X> visitor) throws X {
26: visitor.meet(this);
27: }
28: }
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