/* Copyright (c) 2001-2016, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb;
import org.hsqldb.lib.
HsqlList;
import org.hsqldb.lib.
OrderedHashSet;
import org.hsqldb.lib.
Set;
import org.hsqldb.types.
Type;
/**
* Implementation of column used as assignment target.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.3.0
* @since 2.0.0
*/
public class
ExpressionColumnAccessor extends
Expression {
ColumnSchema column;
ExpressionColumnAccessor(
ColumnSchema column) {
super(
OpTypes.
COLUMN);
this.
column =
column;
this.
dataType =
column.
getDataType();
}
String getAlias() {
return
column.
getNameString();
}
void
collectObjectNames(
Set set) {
set.
add(
column.
getName());
if (
column.
getName().
parent != null) {
set.
add(
column.
getName().
parent);
}
}
String getColumnName() {
return
column.
getNameString();
}
public
ColumnSchema getColumn() {
return
column;
}
RangeVariable getRangeVariable() {
return null;
}
public
HsqlList resolveColumnReferences(
Session session,
RangeGroup rangeGroup, int
rangeCount,
RangeGroup[]
rangeGroups,
HsqlList unresolvedSet, boolean
acceptsSequences) {
return
unresolvedSet;
}
public void
resolveTypes(
Session session,
Expression parent) {}
public
Object getValue(
Session session) {
return null;
}
public
String getSQL() {
return
column.
getName().
statementName;
}
protected
String describe(
Session session, int
blanks) {
return
column.
getName().
name;
}
public
OrderedHashSet getUnkeyedColumns(
OrderedHashSet unresolvedSet) {
return
unresolvedSet;
}
/**
* collects all range variables in expression tree
*/
OrderedHashSet collectRangeVariables(
RangeVariable[]
rangeVariables,
OrderedHashSet set) {
return
set;
}
Expression replaceAliasInOrderBy(
Session session,
Expression[]
columns,
int
length) {
return this;
}
Expression replaceColumnReferences(
RangeVariable range,
Expression[]
list) {
return this;
}
/**
* return true if given RangeVariable is used in expression tree
*/
boolean
hasReference(
RangeVariable range) {
return false;
}
/**
* SIMPLE_COLUMN expressions can be of different Expression subclass types
*/
public boolean
equals(
Expression other) {
if (
other == this) {
return true;
}
if (
other == null) {
return false;
}
if (
opType !=
other.
opType) {
return false;
}
return
column ==
other.
getColumn();
}
void
replaceRangeVariables(
RangeVariable[]
ranges,
RangeVariable[]
newRanges) {}
void
resetColumnReferences() {}
public boolean
isIndexable(
RangeVariable range) {
return false;
}
public boolean
isUnresolvedParam() {
return false;
}
boolean
isDynamicParam() {
return false;
}
public
Type getDataType() {
return
column.
getDataType();
}
}