📄 select.java
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/* Copyright (c) 1995-2000, The Hypersonic SQL 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 Hypersonic SQL 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
* ARE DISCLAIMED. IN NO EVENT SHALL THE HYPERSONIC SQL GROUP,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This software consists of voluntary contributions made by many individuals
* on behalf of the Hypersonic SQL Group.
*
*
* For work added by the HSQL Development Group:
*
* Copyright (c) 2001-2005, 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
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.hsqldb;
import org.hsqldb.HsqlNameManager.HsqlName;
import org.hsqldb.lib.HashMap;
import org.hsqldb.lib.HashSet;
import org.hsqldb.lib.HsqlArrayList;
import org.hsqldb.lib.Iterator;
// fredt@users 20010701 - patch 1.6.1 by hybris
// basic implementation of LIMIT n m
// fredt@users 20020130 - patch 471710 by fredt - LIMIT rewritten
// for SELECT LIMIT n m DISTINCT
// fredt@users 20020221 - patch 513005 by sqlbob@users (RMP)
// type and logging attributes of sIntotable
// fredt@users 20020230 - patch 495938 by johnhobs@users - GROUP BY order
// fred@users 20020522 - patch 1.7.0 - aggregate functions with DISTINCT
// rougier@users 20020522 - patch 552830 - COUNT(DISTINCT)
// fredt@users 20020804 - patch 580347 by dkkopp - view speedup
// tony_lai@users 20021020 - patch 1.7.2 - improved aggregates and HAVING
// boucherb@users 20030811 - patch 1.7.2 - prepared statement support
// fredt@users 20031012 - patch 1.7.2 - better OUTER JOIN implementation
// fredt@users 20031012 - patch 1.7.2 - SQL standard ORDER BY with UNION and other set queries
// fredt@users 200408xx - patch 1.7.2 - correct evaluation of the precedence of nested UNION and other set query
/**
* The compiled representation of an SQL SELECT.
*
* Extended in successive versions of HSQLDB.
*
* @author Thomas Mueller (Hypersonic SQL Group)
* @version 1.8.0
* @since Hypersonic SQL
*/
class Select {
boolean isDistinctSelect;
boolean isAggregated;
private boolean isGrouped;
private HashSet groupColumnNames;
TableFilter[] tFilter;
Expression limitCondition;
Expression queryCondition; // null means no condition
Expression havingCondition; // null means none
Expression[] exprColumns; // 'result', 'group' and 'order' columns
int iResultLen; // number of columns that are 'result'
int iGroupLen; // number of columns that are 'group'
int iHavingLen; // number of columns that are 'group'
int iOrderLen; // number of columns that are 'order'
int[] sortOrder;
int[] sortDirection;
boolean sortUnion; // if true, sort the result of the full union
HsqlName sIntoTable; // null means not select..into
int intoType;
Select[] unionArray; // only set in the first Select in a union chain
int unionMaxDepth; // max unionDepth in chain
Select unionSelect; // null means no union select
int unionType;
int unionDepth;
static final int NOUNION = 0,
UNION = 1,
UNIONALL = 2,
INTERSECT = 3,
EXCEPT = 4;
private boolean simpleLimit; // true if maxrows can be uses as is
Result.ResultMetaData resultMetaData;
/**
* Experimental.
*
* Map the column aliases to expressions in order to resolve alias names
* in WHERE clauses
*
*/
HashMap getColumnAliases() {
HashMap aliasMap = new HashMap();
for (int i = 0; i < iResultLen; i++) {
String alias = exprColumns[i].getAlias();
if (alias != null) {
aliasMap.put(alias, exprColumns[i]);
}
}
return aliasMap;
}
/**
* Method declaration
*
*
* @throws HsqlException
*/
void resolve(Session session) throws HsqlException {
resolveTables();
resolveTypes(session);
setFilterConditions(session);
}
/**
* Method declaration
*
*
* @throws HsqlException
*/
private void resolveTables() throws HsqlException {
// replace the aliases with expressions
for (int i = iResultLen; i < exprColumns.length; i++) {
if (exprColumns[i].getType() == Expression.COLUMN) {
if (exprColumns[i].joinedTableColumnIndex == -1) {
boolean descending = exprColumns[i].isDescending();
exprColumns[i] =
exprColumns[i].getExpressionForAlias(exprColumns,
iResultLen);
if (descending) {
exprColumns[i].setDescending();
}
}
} else {
exprColumns[i].replaceAliases(exprColumns, iResultLen);
}
}
if (queryCondition != null) {
queryCondition.replaceAliases(exprColumns, iResultLen);
}
int len = tFilter.length;
for (int i = 0; i < len; i++) {
resolveTables(tFilter[i]);
}
}
/**
* Converts the types of the columns in set operations to those in the first
* Select.
*/
void resolveUnionColumnTypes() throws HsqlException {
if (unionSelect != null) {
if (unionSelect.iResultLen != iResultLen) {
throw Trace.error(Trace.COLUMN_COUNT_DOES_NOT_MATCH);
}
for (int i = 0; i < iResultLen; i++) {
Expression e = exprColumns[i];
if (!e.isTypeEqual(unionSelect.exprColumns[i])) {
unionSelect.exprColumns[i] =
new Expression(unionSelect.exprColumns[i],
e.getDataType(), e.getColumnSize(),
e.getColumnScale());
}
}
}
}
/**
* Sets the types of all the expressions that have so far resolved.
*
* @throws HsqlException
*/
void resolveTypes(Session session) throws HsqlException {
int len = exprColumns.length;
for (int i = 0; i < len; i++) {
exprColumns[i].resolveTypes(session);
}
if (queryCondition != null) {
queryCondition.resolveTypes(session);
}
}
void resolveTablesUnion(TableFilter f) throws HsqlException {
if (unionArray == null) {
resolveTables(f);
} else {
for (int i = 0; i < unionArray.length; i++) {
unionArray[i].resolveTables(f);
}
}
}
/**
* Resolves the tables for all the Expression in the Select object
* if it is possible to do so with the given TableFilter.
*
* @param f
*
* @throws HsqlException
*/
void resolveTables(TableFilter f) throws HsqlException {
int len = exprColumns.length;
for (int i = 0; i < len; i++) {
exprColumns[i].resolveTables(f);
}
if (queryCondition != null) {
queryCondition.resolveTables(f);
}
}
private void setFilterConditions(Session session) throws HsqlException {
if (queryCondition == null) {
return;
}
for (int i = 0; i < tFilter.length; i++) {
tFilter[i].setConditions(session, queryCondition);
}
}
/**
* Check all Expression have resolved. Return true or false as a result.
* Throw if false and check parameter is true.
*
* @throws HsqlException
*/
boolean checkResolved(boolean check) throws HsqlException {
boolean result = true;
int len = exprColumns.length;
for (int i = 0; i < len; i++) {
result = result && exprColumns[i].checkResolved(check);
}
if (queryCondition != null) {
result = result && queryCondition.checkResolved(check);
}
if (havingCondition != null) {
result = result && havingCondition.checkResolved(check);
}
for (int i = 0; i < tFilter.length; i++) {
if (tFilter[i].filterIndex == null) {
tFilter[i].filterIndex =
tFilter[i].filterTable.getPrimaryIndex();
}
}
return result;
}
/**
* Removes all the TableFilters from the Expressions.
*
* @throws HsqlException
*/
/*
void removeFilters() throws HsqlException {
int len = eColumn.length;
for (int i = 0; i < len; i++) {
eColumn[i].removeFilters();
}
if (eCondition != null) {
eCondition.removeFilters();
}
}
*/
/**
* Returns a single value result or throws if the result has more than
* one row with one value.
*
* @param type data type
* @param session context
* @return the single valued result
* @throws HsqlException
*/
Object getValue(Session session, int type) throws HsqlException {
resolve(session);
Result r = getResult(session, 2); // 2 records are required for test
int size = r.getSize();
int len = r.getColumnCount();
if (len == 1) {
if (size == 0) {
return null;
} else if (size == 1) {
Object o = r.rRoot.data[0];
return r.metaData.colTypes[0] == type ? o
: Column.convertObject(
o, type);
} else {
throw Trace.error(Trace.CARDINALITY_VIOLATION_NO_SUBCLASS);
}
}
HsqlException e =
Trace.error(Trace.CARDINALITY_VIOLATION_NO_SUBCLASS);
throw new HsqlInternalException(e);
}
/**
* Resolves expressions and pepares thre metadata for the result.
*/
void prepareResult(Session session) throws HsqlException {
resolveAll(session, true);
if (iGroupLen > 0) { // has been set in Parser
isGrouped = true;
groupColumnNames = new HashSet();
for (int i = iResultLen; i < iResultLen + iGroupLen; i++) {
// MarcH: this is wrong for a CASE WHEN statement in a SELECT CASE WHEN ...,<something aggregate> statement
// collectColumnName collects no columns if exprColumns[i]'s expressiontype is Expression.CASEWHEN
// collectAllColumnNames collects all columns used in the CASE WHEN statement
// exprColumns[i].collectColumnName(groupColumnNames);
exprColumns[i].collectAllColumnNames(groupColumnNames);
}
}
int len = exprColumns.length;
resultMetaData = new Result.ResultMetaData(len);
Result.ResultMetaData rmd = resultMetaData;
// tony_lai@users having
int groupByStart = iResultLen;
int groupByEnd = groupByStart + iGroupLen;
int orderByStart = groupByEnd + iHavingLen;
int orderByEnd = orderByStart + iOrderLen;
for (int i = 0; i < len; i++) {
Expression e = exprColumns[i];
rmd.colTypes[i] = e.getDataType();
rmd.colSizes[i] = e.getColumnSize();
rmd.colScales[i] = e.getColumnScale();
if (e.isAggregate()) {
isAggregated = true;
}
if (i >= groupByStart && i < groupByEnd
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