/* 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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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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package org.hsqldb;
import org.hsqldb.
ParserDQL.
CompileContext;
import org.hsqldb.error.
Error;
import org.hsqldb.error.
ErrorCode;
import org.hsqldb.lib.
OrderedHashSet;
import org.hsqldb.navigator.
RowSetNavigatorData;
import org.hsqldb.result.
Result;
/**
* Implementation of Statement for PSM statements with expressions.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 2.2.9
* @since 1.9.0
*/
public class
StatementExpression extends
StatementDMQL {
Expression expression;
/**
* for RETURN and flow control
*/
StatementExpression(
Session session,
CompileContext compileContext,
int
type,
Expression expression) {
super(
type,
StatementTypes.
X_SQL_CONTROL, null);
switch (
type) {
case
StatementTypes.
RETURN :
case
StatementTypes.
CONDITION :
break;
default :
throw
Error.
runtimeError(
ErrorCode.
U_S0500, "");
}
isTransactionStatement = false;
this.
expression =
expression;
setDatabaseObjects(
session,
compileContext);
checkAccessRights(
session);
}
public
String getSQL() {
StringBuffer sb = new
StringBuffer();
switch (
type) {
case
StatementTypes.
RETURN :
return
sql;
case
StatementTypes.
CONDITION :
sb.
append(
expression.
getSQL());
break;
}
return
sb.
toString();
}
TableDerived[]
getSubqueries(
Session session) {
OrderedHashSet subQueries = null;
if (
expression != null) {
subQueries =
expression.
collectAllSubqueries(
subQueries);
}
if (
subQueries == null ||
subQueries.
size() == 0) {
return
TableDerived.
emptyArray;
}
TableDerived[]
subQueryArray = new
TableDerived[
subQueries.
size()];
subQueries.
toArray(
subQueryArray);
for (int
i = 0;
i <
subqueries.length;
i++) {
subQueryArray[
i].
prepareTable(
session);
}
return
subQueryArray;
}
protected
String describe(
Session session, int
blanks) {
StringBuffer sb = new
StringBuffer();
sb.
append('\n');
for (int
i = 0;
i <
blanks;
i++) {
sb.
append(' ');
}
sb.
append(
Tokens.
T_STATEMENT);
return
sb.
toString();
}
public
Result execute(
Session session) {
Result result;
try {
if (
subqueries.length > 0) {
materializeSubQueries(
session);
}
result =
getResult(
session);
} catch (
Throwable t) {
result =
Result.
newErrorResult(
t);
}
if (
result.
isError()) {
result.
getException().
setStatementType(
group,
type);
}
return
result;
}
Result getResult(
Session session) {
switch (
type) {
case
StatementTypes.
RETURN :
case
StatementTypes.
CONDITION :
Result result =
expression.
getResult(
session);
// data navigator has statement scope and will be cleared at the end of statement
if (
result.
isData()) {
RowSetNavigatorData navigator =
new
RowSetNavigatorData(
session,
result.
getNavigator());
result.
setNavigator(
navigator);
}
return
result;
default :
throw
Error.
runtimeError(
ErrorCode.
U_S0500, "");
}
}
public void
resolve(
Session session) {}
String describeImpl(
Session session) throws
Exception {
return
getSQL();
}
void
collectTableNamesForRead(
OrderedHashSet set) {
for (int
i = 0;
i <
subqueries.length;
i++) {
if (
subqueries[
i].
queryExpression != null) {
subqueries[
i].
queryExpression.
getBaseTableNames(
set);
}
}
for (int
i = 0;
i <
routines.length;
i++) {
set.
addAll(
routines[
i].
getTableNamesForRead());
}
}
void
collectTableNamesForWrite(
OrderedHashSet set) {}
}