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org.eclipse.persistence.internal.expressions.SQLSelectStatement Maven / Gradle / Ivy
EclipseLink build based upon Git transaction ecdf3c32c4
/*
* Copyright (c) 1998, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0,
* or the Eclipse Distribution License v. 1.0 which is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
*/
// Contributors:
// Oracle - initial API and implementation from Oracle TopLink
// 20/11/2012-2.5 Guy Pelletier
// - 394524: Invalid query key [...] in expression
// 04/30/2014-2.6 Lukas Jungmann
// - 380101: Invalid MySQL SQL syntax in query with LIMIT and FOR UPDATE
// IBM - Bug 537795: CASE THEN and ELSE scalar expression Constants should not be casted to CASE operand type
package org.eclipse.persistence.internal.expressions;
import static org.eclipse.persistence.queries.ReadAllQuery.Direction.CHILD_TO_PARENT;
import java.io.CharArrayWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.Vector;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.exceptions.QueryException;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.expressions.ExpressionBuilder;
import org.eclipse.persistence.expressions.ExpressionOperator;
import org.eclipse.persistence.history.AsOfClause;
import org.eclipse.persistence.internal.databaseaccess.DatabaseCall;
import org.eclipse.persistence.internal.databaseaccess.DatabasePlatform;
import org.eclipse.persistence.internal.databaseaccess.DatasourcePlatform;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.helper.DatabaseTable;
import org.eclipse.persistence.internal.helper.FunctionField;
import org.eclipse.persistence.internal.helper.Helper;
import org.eclipse.persistence.internal.helper.NonSynchronizedVector;
import org.eclipse.persistence.internal.history.DecoratedDatabaseTable;
import org.eclipse.persistence.internal.history.UniversalAsOfClause;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.mappings.AggregateCollectionMapping;
import org.eclipse.persistence.mappings.AggregateObjectMapping;
import org.eclipse.persistence.mappings.DatabaseMapping;
import org.eclipse.persistence.mappings.DirectCollectionMapping;
import org.eclipse.persistence.mappings.ManyToManyMapping;
import org.eclipse.persistence.mappings.ObjectReferenceMapping;
import org.eclipse.persistence.mappings.OneToManyMapping;
import org.eclipse.persistence.mappings.OneToOneMapping;
import org.eclipse.persistence.queries.DatabaseQuery;
import org.eclipse.persistence.queries.ObjectLevelReadQuery;
import org.eclipse.persistence.queries.ReadAllQuery;
import org.eclipse.persistence.queries.ReadQuery;
import org.eclipse.persistence.queries.SQLCall;
/**
* Purpose : Print SELECT statement.
*
Responsibilities :
* Print SELECT statement.
*
* @author Dorin Sandu
* @since TOPLink/Java 1.0
*/
public class SQLSelectStatement extends SQLStatement {
/** Query this statement is associated to (used for SQL query options). */
protected ReadQuery query;
/** Flag used to indicate field names should use unique aliases */
protected boolean useUniqueFieldAliases;
/** Counter to generate unique alias names */
protected int fieldCounter=0;
/** Fields being selected (can include expressions). */
protected Vector fields;
/** Fields not being selected (can include expressions). */
protected List nonSelectFields;
/** Tables being selected from. */
protected List tables;
/** Used for "Select Distinct" option. */
protected short distinctState;
/** Order by clause for read all queries. */
protected List orderByExpressions;
/** Group by clause for report queries. */
protected List groupByExpressions;
/** Union clause. */
protected List unionExpressions;
/** Having clause for report queries. */
protected Expression havingExpression;
/** Used for pessimistic locking ie. "For Update". */
protected ForUpdateClause forUpdateClause;
/** Used for report query or counts so we know how to treat distincts. */
protected boolean isAggregateSelect;
/** Used for DB2 style from clause outer joins. */
protected List outerJoinExpressionHolders;
/** Used for Oracle Hierarchical Queries */
protected Expression startWithExpression;
protected Expression connectByExpression;
protected List orderSiblingsByExpressions;
protected ReadAllQuery.Direction direction;
/** Variables used for aliasing and normalizing. */
protected boolean requiresAliases;
protected Map tableAliases;
protected DatabaseTable lastTable;
protected DatabaseTable currentAlias;
protected int currentAliasNumber;
/** Used for subselects. */
protected SQLSelectStatement parentStatement;
/** It is used by subselect to re-normalize joins */
protected Map optimizedClonedExpressions;
/** Used for caching the field alias written to the query */
protected Map fieldAliases;
protected boolean shouldCacheFieldAliases;
public SQLSelectStatement() {
this.fields = org.eclipse.persistence.internal.helper.NonSynchronizedVector.newInstance(2);
this.tables = new ArrayList(4);
this.requiresAliases = false;
this.useUniqueFieldAliases=false;
this.isAggregateSelect = false;
this.distinctState = ObjectLevelReadQuery.UNCOMPUTED_DISTINCT;
this.currentAliasNumber = 0;
}
public void addField(DatabaseField field) {
getFields().addElement(field);
}
/**
* INTERNAL: adds an expression to the fields. set a flag if the expression
* is for and aggregate function.
*/
public void addField(Expression expression) {
if (expression instanceof FunctionExpression) {
if (((FunctionExpression)expression).getOperator().isAggregateOperator()) {
setIsAggregateSelect(true);
}
}
getFields().add(expression);
}
/**
* When distinct is used with order by the ordered fields must be in the select clause.
*/
protected void addOrderByExpressionToSelectForDistinct() {
for (Expression orderExpression : getOrderByExpressions()) {
Expression fieldExpression = orderExpression;
while (fieldExpression.isFunctionExpression() && (fieldExpression.getOperator().isOrderOperator())) {
fieldExpression = ((FunctionExpression)fieldExpression).getBaseExpression();
}
// Changed to call a method to loop through the fields vector and check each element
// individually. Jon D. May 4, 2000 for pr 7811
if ((fieldExpression.selectIfOrderedBy()) && !fieldsContainField(getFields(), fieldExpression)) {
addField(fieldExpression);
}
}
}
/**
* Add a table to the statement. The table will
* be used in the FROM part of the SQL statement.
*/
public void addTable(DatabaseTable table) {
if (!getTables().contains(table)) {
getTables().add(table);
}
}
/**
* ADVANCED:
* If a platform is Informix, then the outer join must be in the FROM clause.
* This is used internally by EclipseLink for building Informix outer join syntax which differs from
* other platforms (Oracle,Sybase) that print the outer join in the WHERE clause and from DB2 which prints
* the OuterJoinedAliases passed in to keep track of tables used for outer join so no normal join is given.
* This syntax is old for Informix, so should probably be removed.
*/
public void appendFromClauseForInformixOuterJoin(ExpressionSQLPrinter printer, List outerJoinedAliases) throws IOException {
Writer writer = printer.getWriter();
// Print outer joins
boolean firstTable = true;
for (OuterJoinExpressionHolder holder : getOuterJoinExpressionsHolders()) {
QueryKeyExpression outerExpression = (QueryKeyExpression)holder.joinExpression;
CompoundExpression relationExpression = (CompoundExpression)holder.outerJoinedMappingCriteria;// get expression for multiple table case
// CR#3083929 direct collection/map mappings do not have reference descriptor.
DatabaseTable targetTable = null;
if (outerExpression.getMapping().isDirectCollectionMapping()) {
targetTable = ((DirectCollectionMapping)outerExpression.getMapping()).getReferenceTable();
} else {
targetTable = outerExpression.getMapping().getReferenceDescriptor().getTables().get(0);
}
// Grab the source table from the mapping not just the first table
// from the descriptor. In an joined inheritance hierarchy, the
// fk used in the outer join may be from a subclasses's table .
DatabaseTable sourceTable;
if (outerExpression.getMapping().isObjectReferenceMapping() && ((ObjectReferenceMapping) outerExpression.getMapping()).isForeignKeyRelationship()) {
sourceTable = (outerExpression.getMapping().getFields().get(0)).getTable();
} else {
sourceTable = ((ObjectExpression)outerExpression.getBaseExpression()).getDescriptor().getTables().get(0);
}
DatabaseTable sourceAlias = outerExpression.getBaseExpression().aliasForTable(sourceTable);
DatabaseTable targetAlias = outerExpression.aliasForTable(targetTable);
if (!(outerJoinedAliases.contains(sourceAlias) || outerJoinedAliases.contains(targetAlias))) {
if (!firstTable) {
writer.write(", ");
}
firstTable = false;
writer.write(sourceTable.getQualifiedNameDelimited(printer.getPlatform()));
outerJoinedAliases.add(sourceAlias);
writer.write(" ");
writer.write(sourceAlias.getQualifiedNameDelimited(printer.getPlatform()));
if (outerExpression.getMapping().isManyToManyMapping()) {// for many to many mappings, you need to do some funky stuff to get the relation table's alias
DatabaseTable newTarget = ((ManyToManyMapping)outerExpression.getMapping()).getRelationTable();
DatabaseTable newAlias = relationExpression.aliasForTable(newTarget);
writer.write(", OUTER ");// need to outer join only to relation table for many-to-many case in Informix
writer.write(newTarget.getQualifiedNameDelimited(printer.getPlatform()));
writer.write(" ");
outerJoinedAliases.add(newAlias);
writer.write(newAlias.getQualifiedNameDelimited(printer.getPlatform()));
} else if (outerExpression.getMapping().isDirectCollectionMapping()) {// for many to many mappings, you need to do some funky stuff to get the relation table's alias
DatabaseTable newTarget = ((DirectCollectionMapping)outerExpression.getMapping()).getReferenceTable();
DatabaseTable newAlias = relationExpression.aliasForTable(newTarget);
writer.write(", OUTER ");
writer.write(newTarget.getQualifiedNameDelimited(printer.getPlatform()));
writer.write(" ");
outerJoinedAliases.add(newAlias);
writer.write(newAlias.getQualifiedNameDelimited(printer.getPlatform()));
} else {// do normal outer stuff for Informix
for (Enumeration target = outerExpression.getMapping().getReferenceDescriptor().getTables().elements();
target.hasMoreElements();) {
DatabaseTable newTarget = (DatabaseTable)target.nextElement();
DatabaseTable newAlias = outerExpression.aliasForTable(newTarget);
writer.write(", OUTER ");
writer.write(newTarget.getQualifiedNameDelimited(printer.getPlatform()));
writer.write(" ");
outerJoinedAliases.add(newAlias);
writer.write(newAlias.getQualifiedNameDelimited(printer.getPlatform()));
}
}
}
}
}
/**
* ADVANCED:
* Appends the SQL standard outer join clause, and some variation per platform.
* Most platforms use this syntax, support is also offered for Oracle to join in the where clause (although it should use the FROM clause as the WHERE clause is obsolete).
* This is also used for inner joins when configured in the platform.
*/
public void appendFromClauseForOuterJoin(ExpressionSQLPrinter printer, List outerJoinedAliases, Collection aliasesOfTablesToBeLocked, boolean shouldPrintUpdateClauseForAllTables) throws IOException {
Writer writer = printer.getWriter();
AbstractSession session = printer.getSession();
DatabasePlatform platform = session.getPlatform();
// Print outer joins
boolean firstTable = true;
boolean requiresEscape = false; // Checks if the JDBC closing escape syntax is needed.
boolean usesHistory = (getBuilder() != null) && getBuilder().hasAsOfClause();
int nSize = getOuterJoinExpressionsHolders().size();
for (OuterJoinExpressionHolder holder : getOuterJoinExpressionsHolders()) {
holder.process(usesHistory);
}
if(nSize > 1) {
sortOuterJoinExpressionHolders(getOuterJoinExpressionsHolders());
}
for (OuterJoinExpressionHolder holder : outerJoinExpressionHolders) {
ObjectExpression outerExpression = holder.joinExpression;
boolean isOuterJoin = (outerExpression == null) || outerExpression.shouldUseOuterJoin();
DatabaseTable targetTable = holder.targetTable;
DatabaseTable sourceTable = holder.sourceTable;
DatabaseTable sourceAlias = holder.sourceAlias;
DatabaseTable targetAlias = holder.targetAlias;
if (!outerJoinedAliases.contains(targetAlias)) {
if (!outerJoinedAliases.contains(sourceAlias)) {
if (requiresEscape && session.getPlatform().shouldUseJDBCOuterJoinSyntax()) {
writer.write("}");
}
if (!firstTable) {
writer.write(",");
}
if (platform.shouldUseJDBCOuterJoinSyntax()) {
writer.write(platform.getJDBCOuterJoinString());
}
requiresEscape = true;
firstTable = false;
sourceTable.printSQL(printer);
outerJoinedAliases.add(sourceAlias);
writer.write(" ");
if (sourceAlias.isDecorated()) {
((DecoratedDatabaseTable)sourceAlias).getAsOfClause().printSQL(printer);
writer.write(" ");
}
sourceAlias.printSQL(printer);
printForUpdateClauseOnJoin(sourceAlias, printer, shouldPrintUpdateClauseForAllTables, aliasesOfTablesToBeLocked, platform);
}
if (outerExpression == null) {
holder.printAdditionalJoins(printer, outerJoinedAliases, aliasesOfTablesToBeLocked, shouldPrintUpdateClauseForAllTables);
} else {
DatabaseTable relationTable = outerExpression.getRelationTable();
boolean hasAdditionalJoinExpressions = holder.hasAdditionalJoinExpressions();
boolean isMapKeyObject = holder.hasMapKeyHolder();
Expression additionalOnExpression = outerExpression.getOnClause();
if (relationTable == null) {
if (outerExpression.isDirectCollection()) {
// Append the join clause,
// If this is a direct collection, join to direct table.
Expression onExpression = holder.outerJoinedMappingCriteria;
DatabaseTable newAlias = onExpression.aliasForTable(targetTable);
if (isOuterJoin) {
writer.write(" LEFT OUTER JOIN ");
} else {
writer.write(" JOIN ");
}
targetTable.printSQL(printer);
writer.write(" ");
if (newAlias.isDecorated()) {
((DecoratedDatabaseTable)newAlias).getAsOfClause().printSQL(printer);
writer.write(" ");
}
outerJoinedAliases.add(newAlias);
newAlias.printSQL(printer);
printForUpdateClauseOnJoin(newAlias, printer, shouldPrintUpdateClauseForAllTables, aliasesOfTablesToBeLocked, platform);
printOnClause(onExpression.and(additionalOnExpression), printer, platform);
} else {
// Must outerjoin each of the targets tables.
// The first table is joined with the mapping join criteria,
// the rest of the tables are joined with the additional join criteria.
if (isOuterJoin) {
writer.write(" LEFT OUTER JOIN ");
} else {
writer.write(" JOIN ");
}
if (hasAdditionalJoinExpressions && platform.supportsNestingOuterJoins()) {
writer.write("(");
}
targetTable.printSQL(printer);
writer.write(" ");
if (targetAlias.isDecorated()) {
((DecoratedDatabaseTable)targetAlias).getAsOfClause().printSQL(printer);
writer.write(" ");
}
outerJoinedAliases.add(targetAlias);
targetAlias.printSQL(printer);
printForUpdateClauseOnJoin(targetAlias, printer, shouldPrintUpdateClauseForAllTables, aliasesOfTablesToBeLocked, platform);
if (hasAdditionalJoinExpressions && platform.supportsNestingOuterJoins()) {
holder.printAdditionalJoins(printer, outerJoinedAliases, aliasesOfTablesToBeLocked, shouldPrintUpdateClauseForAllTables);
writer.write(")");
}
Expression sourceToTargetJoin = holder.outerJoinedMappingCriteria;
if (additionalOnExpression != null) {
if (sourceToTargetJoin == null) {
sourceToTargetJoin = additionalOnExpression;
} else {
sourceToTargetJoin = sourceToTargetJoin.and(additionalOnExpression);
}
}
printOnClause(sourceToTargetJoin, printer, platform);
if (hasAdditionalJoinExpressions && !platform.supportsNestingOuterJoins()) {
holder.printAdditionalJoins(printer, outerJoinedAliases, aliasesOfTablesToBeLocked, shouldPrintUpdateClauseForAllTables);
}
}
} else {
// Bug#4240751 Treat ManyToManyMapping separately for out join
// Must outer join each of the targets tables.
// The first table is joined with the mapping join criteria,
// the rest of the tables are joined with the additional join criteria.
// For example: EMPLOYEE t1 LEFT OUTER JOIN (PROJ_EMP t3 LEFT OUTER JOIN PROJECT t0 ON (t0.PROJ_ID = t3.PROJ_ID)) ON (t3.EMP_ID = t1.EMP_ID)
// Now OneToOneMapping also may have relation table.
DatabaseTable relationAlias = holder.outerJoinedMappingCriteria.aliasForTable(relationTable);
DatabaseTable mapKeyAlias = null;
DatabaseTable mapKeyTable = null;
List tablesInOrder = new ArrayList();
// glassfish issue 2440: store aliases instead of tables
// in the tablesInOrder. This allows to distinguish source
// and target table in case of an self referencing relationship.
tablesInOrder.add(sourceAlias);
tablesInOrder.add(relationAlias);
tablesInOrder.add(targetAlias);
if (isMapKeyObject) {
// Need to also join the map key key.
mapKeyAlias = holder.mapKeyHolder.targetAlias;
mapKeyTable = holder.mapKeyHolder.targetTable;
tablesInOrder.add(mapKeyAlias);
}
TreeMap indexToExpressionMap = new TreeMap();
mapTableIndexToExpression(holder.outerJoinedMappingCriteria, indexToExpressionMap, tablesInOrder);
Expression sourceToRelationJoin = (Expression)indexToExpressionMap.get(Integer.valueOf(1));
Expression relationToTargetJoin = (Expression)indexToExpressionMap.get(Integer.valueOf(2));
Expression relationToKeyJoin = null;
if (isMapKeyObject) {
relationToKeyJoin = (Expression)indexToExpressionMap.get(Integer.valueOf(3));
}
if (outerExpression.shouldUseOuterJoin()) {
writer.write(" LEFT OUTER JOIN ");
} else {
writer.write(" JOIN ");
}
if (platform.supportsNestingOuterJoins()) {
writer.write("(");
}
relationTable.printSQL(printer);
writer.write(" ");
if (relationAlias.isDecorated()) {
((DecoratedDatabaseTable)relationAlias).getAsOfClause().printSQL(printer);
writer.write(" ");
}
outerJoinedAliases.add(relationAlias);
relationAlias.printSQL(printer);
printForUpdateClauseOnJoin(relationAlias, printer, shouldPrintUpdateClauseForAllTables, aliasesOfTablesToBeLocked, platform);
if (!platform.supportsNestingOuterJoins()) {
printOnClause(sourceToRelationJoin.and(additionalOnExpression), printer, platform);
}
if (isMapKeyObject) {
// Append join to map key.
if (isOuterJoin && !session.getPlatform().supportsANSIInnerJoinSyntax()) {
writer.write(" LEFT OUTER");
}
writer.write(" JOIN ");
mapKeyTable.printSQL(printer);
writer.write(" ");
if (mapKeyAlias.isDecorated()) {
((DecoratedDatabaseTable)mapKeyAlias).getAsOfClause().printSQL(printer);
writer.write(" ");
}
outerJoinedAliases.add(mapKeyAlias);
mapKeyAlias.printSQL(printer);
printForUpdateClauseOnJoin(mapKeyAlias, printer, shouldPrintUpdateClauseForAllTables, aliasesOfTablesToBeLocked, platform);
printOnClause(relationToKeyJoin.and(additionalOnExpression), printer, platform);
if (holder.mapKeyHolder.hasAdditionalJoinExpressions()) {
holder.mapKeyHolder.printAdditionalJoins(printer, outerJoinedAliases, aliasesOfTablesToBeLocked, shouldPrintUpdateClauseForAllTables);
}
}
if (isOuterJoin && !session.getPlatform().supportsANSIInnerJoinSyntax()) {
// if the DB does not support 'JOIN', do a left outer
// join instead. This will give the same result because
// the left table is a join table and has therefore
// no rows that are not in the right table.
writer.write(" LEFT OUTER");
}
writer.write(" JOIN ");
targetTable.printSQL(printer);
writer.write(" ");
if (targetAlias.isDecorated()) {
((DecoratedDatabaseTable)targetAlias).getAsOfClause().printSQL(printer);
writer.write(" ");
}
outerJoinedAliases.add(targetAlias);
targetAlias.printSQL(printer);
printForUpdateClauseOnJoin(targetAlias, printer, shouldPrintUpdateClauseForAllTables, aliasesOfTablesToBeLocked, platform);
printOnClause(relationToTargetJoin, printer, platform);
if (hasAdditionalJoinExpressions) {
holder.printAdditionalJoins(printer, outerJoinedAliases, aliasesOfTablesToBeLocked, shouldPrintUpdateClauseForAllTables);
}
if (platform.supportsNestingOuterJoins()) {
writer.write(")");
printOnClause(sourceToRelationJoin, printer, platform);
}
}
}
}
}
if (requiresEscape && session.getPlatform().shouldUseJDBCOuterJoinSyntax()) {
writer.write("}");
}
}
/**
* Print the outer join ON clause.
* Some databases do not allow brackets.
*/
protected void printOnClause(Expression onClause, ExpressionSQLPrinter printer, DatabasePlatform platform) throws IOException {
printer.getWriter().write(" ON ");
if (!platform.supportsOuterJoinsWithBrackets()) {
((RelationExpression)onClause).printSQLNoParens(printer);
} else {
onClause.printSQL(printer);
}
}
/**
* Print the FOR UPDATE clause after each join if required.
*/
protected void printForUpdateClauseOnJoin(DatabaseTable alias, ExpressionSQLPrinter printer, boolean shouldPrintUpdateClauseForAllTables, Collection aliasesOfTablesToBeLocked, DatabasePlatform platform) {
if (shouldPrintUpdateClauseForAllTables || (aliasesOfTablesToBeLocked != null && aliasesOfTablesToBeLocked.remove(alias))) {
getForUpdateClause().printSQL(printer, this);
}
}
/**
* Print the from clause.
* This includes outer joins, these must be printed before the normal join to ensure that the source tables are not joined again.
* Outer joins are not printed in the FROM clause on Oracle or Sybase.
*/
public void appendFromClauseToWriter(ExpressionSQLPrinter printer) throws IOException {
Writer writer = printer.getWriter();
AbstractSession session = printer.getSession();
writer.write(" FROM ");
// Print outer joins
boolean firstTable = true;
List outerJoinedAliases = new ArrayList(4); // Must keep track of tables used for outer join so no normal join is given
// prepare to lock tables if required
boolean shouldPrintUpdateClause = printer.getPlatform().shouldPrintForUpdateClause()
&& !printer.getPlatform().shouldPrintLockingClauseAfterWhereClause()
&& (getForUpdateClause() != null);
Collection aliasesOfTablesToBeLocked = null;
boolean shouldPrintUpdateClauseForAllTables = false;
if (shouldPrintUpdateClause) {
aliasesOfTablesToBeLocked = getForUpdateClause().getAliasesOfTablesToBeLocked(this);
shouldPrintUpdateClauseForAllTables = aliasesOfTablesToBeLocked.size() == getTableAliases().size();
}
if (hasOuterJoinExpressions()) {
if (session.getPlatform().isInformixOuterJoin()) {
appendFromClauseForInformixOuterJoin(printer, outerJoinedAliases);
} else if (!session.getPlatform().shouldPrintOuterJoinInWhereClause() || !session.getPlatform().shouldPrintInnerJoinInWhereClause()) {
appendFromClauseForOuterJoin(printer, outerJoinedAliases, aliasesOfTablesToBeLocked, shouldPrintUpdateClauseForAllTables);
}
firstTable = false;
}
// If there are no table aliases it means the query was malformed,
// most likely the wrong builder was used, or wrong builder on the left in a sub-query.
if (getTableAliases().isEmpty()) {
throw QueryException.invalidBuilderInQuery(null);// Query is set in execute.
}
// Print tables for normal join
for (DatabaseTable alias : getTableAliases().keySet()) {
if (!outerJoinedAliases.contains(alias)) {
DatabaseTable table = getTableAliases().get(alias);
if (requiresAliases()) {
if (!firstTable) {
writer.write(", ");
}
firstTable = false;
table.printSQL(printer);
writer.write(" ");
if (alias.isDecorated()) {
((DecoratedDatabaseTable)alias).getAsOfClause().printSQL(printer);
writer.write(" ");
}
alias.printSQL(printer);
} else {
table.printSQL(printer);
if (alias.isDecorated()) {
writer.write(" ");
((DecoratedDatabaseTable)alias).getAsOfClause().printSQL(printer);
}
}
if (shouldPrintUpdateClause) {
if (shouldPrintUpdateClauseForAllTables || aliasesOfTablesToBeLocked.remove(alias)) {
getForUpdateClause().printSQL(printer, this);
}
}
}
}
}
/**
* This method will append the group by clause to the end of the
* select statement.
*/
public void appendGroupByClauseToWriter(ExpressionSQLPrinter printer) throws IOException {
if (getGroupByExpressions().isEmpty()) {
return;
}
printer.getWriter().write(" GROUP BY ");
Vector newFields = new Vector();
// to avoid printing a comma before the first field
printer.setIsFirstElementPrinted(false);
for (Expression expression : getGroupByExpressions()) {
// if (expression.isObjectExpression() && ((ObjectExpression)expression).getDescriptor() != null){
//in the case where the user is grouping by an entity we need to change this to the PKs
// for (String field : ((ObjectExpression)expression).getDescriptor().getPrimaryKeyFieldNames()){
// writeFieldsFromExpression(printer, expression.getField(field), newFields);
// }
// }else{
writeFieldsFromExpression(printer, expression, newFields);
// }
}
}
/**
* This method will append the Hierarchical Query Clause to the end of the
* select statement
*/
public void appendHierarchicalQueryClauseToWriter(ExpressionSQLPrinter printer) throws IOException {
Expression startWith = getStartWithExpression();
Expression connectBy = getConnectByExpression();
List orderSiblingsBy = getOrderSiblingsByExpressions();
//Create the START WITH CLAUSE
if (startWith != null) {
printer.getWriter().write(" START WITH ");
startWith.printSQL(printer);
}
if (connectBy != null) {
if (!connectBy.isQueryKeyExpression()) {
throw QueryException.illFormedExpression(connectBy);
}
printer.getWriter().write(" CONNECT BY ");
DatabaseMapping mapping = ((QueryKeyExpression)connectBy).getMapping();
ClassDescriptor descriptor = mapping.getDescriptor();
//only works for these kinds of mappings. The data isn't hierarchical otherwise
//Should also check that the source class and target class are the same.
Map foreignKeys = null;
if (mapping.isOneToManyMapping()) {
OneToManyMapping otm = (OneToManyMapping)mapping;
foreignKeys = otm.getTargetForeignKeyToSourceKeys();
} else if (mapping.isOneToOneMapping()) {
OneToOneMapping oto = (OneToOneMapping)mapping;
foreignKeys = oto.getSourceToTargetKeyFields();
} else if (mapping.isAggregateCollectionMapping()) {
AggregateCollectionMapping acm = (AggregateCollectionMapping)mapping;
foreignKeys = acm.getTargetForeignKeyToSourceKeys();
} else {
throw QueryException.invalidQueryKeyInExpression(connectBy);
}
DatabaseTable defaultTable = descriptor.getDefaultTable();
String tableName = "";
//determine which table name to use
if (requiresAliases()) {
tableName = getBuilder().aliasForTable(defaultTable).getName();
} else {
tableName = defaultTable.getNameDelimited(printer.getPlatform());
}
if ((foreignKeys != null) && !foreignKeys.isEmpty()) {
//get the source and target fields.
Iterator sourceKeys = foreignKeys.keySet().iterator();
//for each source field, get the target field and create the link. If there's
//only one, use the simplest version without ugly bracets
if (foreignKeys.size() > 1) {
printer.getWriter().write("((");
}
DatabaseField source = (DatabaseField)sourceKeys.next();
DatabaseField target = (DatabaseField)foreignKeys.get(source);
ReadAllQuery.Direction direction = getDirection() != null ? getDirection() : ReadAllQuery.Direction.getDefault(mapping);
if (direction == CHILD_TO_PARENT) {
printer.getWriter().write("PRIOR " + tableName + "." + source.getNameDelimited(printer.getPlatform()));
printer.getWriter().write(" = " + tableName + "." + target.getNameDelimited(printer.getPlatform()));
} else {
printer.getWriter().write(tableName + "." + source.getNameDelimited(printer.getPlatform()));
printer.getWriter().write(" = PRIOR " + tableName + "." + target.getNameDelimited(printer.getPlatform()));
}
while (sourceKeys.hasNext()) {
printer.getWriter().write(") AND (");
source = (DatabaseField)sourceKeys.next();
target = (DatabaseField)foreignKeys.get(source);
if (direction == CHILD_TO_PARENT) {
printer.getWriter().write("PRIOR " + tableName + "." + source.getNameDelimited(printer.getPlatform()));
printer.getWriter().write(" = " + tableName + "." + target.getNameDelimited(printer.getPlatform()));
} else {
printer.getWriter().write(tableName + "." + source.getNameDelimited(printer.getPlatform()));
printer.getWriter().write(" = PRIOR " + tableName + "." + target.getNameDelimited(printer.getPlatform()));
}
}
if (foreignKeys.size() > 1) {
printer.getWriter().write("))");
}
}
}
if ((orderSiblingsBy != null) && !orderSiblingsBy.isEmpty()) {
printer.getWriter().write(" ORDER SIBLINGS BY ");
for (Iterator iterator = orderSiblingsBy.iterator(); iterator.hasNext(); ) {
Expression expression = iterator.next();
expression.printSQL(printer);
if (iterator.hasNext()) {
printer.getWriter().write(", ");
}
}
}
}
/**
* This method will append the order clause to the end of the
* select statement.
*/
public void appendOrderClauseToWriter(ExpressionSQLPrinter printer) throws IOException {
if (!hasOrderByExpressions()) {
return;
}
printer.getWriter().write(" ORDER BY ");
for (Iterator expressionsEnum = getOrderByExpressions().iterator(); expressionsEnum.hasNext();) {
Expression expression = (Expression)expressionsEnum.next();
expression.printSQL(printer);
if (expressionsEnum.hasNext()) {
printer.getWriter().write(", ");
}
}
}
/**
* This method will append the union clause to the end of the
* select statement.
*/
public void appendUnionClauseToWriter(ExpressionSQLPrinter printer) throws IOException {
if (!hasUnionExpressions()) {
return;
}
for (Iterator expressionsEnum = getUnionExpressions().iterator(); expressionsEnum.hasNext();) {
Expression expression = (Expression)expressionsEnum.next();
printer.getWriter().write(" ");
expression.printSQL(printer);
printer.printString(")");
}
}
/**
* This method will append the for update clause to the end of the
* select statement.
*/
public void appendForUpdateClause(ExpressionSQLPrinter printer) {
if (getForUpdateClause() != null) {
getForUpdateClause().printSQL(printer, this);
}
}
/**
* INTERNAL: Alias the tables in all of our nodes.
*/
public void assignAliases(Vector allExpressions) {
// For sub-selects all statements must share aliasing information.
// For CR#2627019
currentAliasNumber = getCurrentAliasNumber();
ExpressionIterator iterator = new ExpressionIterator() {
@Override
public void iterate(Expression each) {
currentAliasNumber = each.assignTableAliasesStartingAt(currentAliasNumber);
}
};
if (allExpressions.isEmpty()) {
// bug 3878553 - ensure aliases are always assigned for when required .
if ((getBuilder() != null) && requiresAliases()) {
getBuilder().assignTableAliasesStartingAt(currentAliasNumber);
}
} else {
for (Enumeration expressionEnum = allExpressions.elements();
expressionEnum.hasMoreElements();) {
Expression expression = (Expression)expressionEnum.nextElement();
iterator.iterateOn(expression);
}
}
// For sub-selects update aliasing information of all statements.
// For CR#2627019
setCurrentAliasNumber(currentAliasNumber);
}
/**
* Build the call, setting the query first, this is required in some cases when the query info is required to print the SQL.
*/
public DatabaseCall buildCall(AbstractSession session, DatabaseQuery query) {
SQLCall call = new SQLCall();
call.setQuery(query);
call.returnManyRows();
Writer writer = new CharArrayWriter(200);
ExpressionSQLPrinter printer = new ExpressionSQLPrinter(session, getTranslationRow(), call, requiresAliases(), getBuilder());
printer.setWriter(writer);
session.getPlatform().printSQLSelectStatement(call, printer, this);
call.setSQLString(writer.toString());
return call;
}
/**
* Print the SQL representation of the statement on a stream.
*/
@Override
public DatabaseCall buildCall(AbstractSession session) {
return buildCall(session, null);
}
/**
* INTERNAL:
* This is used by cursored stream to determine if an expression used distinct as the size must account for this.
*/
public void computeDistinct() {
ExpressionIterator iterator = new ExpressionIterator() {
@Override
public void iterate(Expression expression) {
if (expression.isQueryKeyExpression() && ((QueryKeyExpression)expression).shouldQueryToManyRelationship()) {
// Aggregate should only use distinct as specified by the user.
if (!isDistinctComputed()) {
useDistinct();
}
}
}
};
if (getWhereClause() != null) {
iterator.iterateOn(getWhereClause());
}
}
public boolean isSubSelect() {
return (getParentStatement() != null);
}
/**
* INTERNAL:
* It is used by subqueries to avoid duplicate joins.
*/
public Map getOptimizedClonedExpressions() {
// Lazily Initialized only to be used by subqueries.
if (optimizedClonedExpressions == null) {
optimizedClonedExpressions = new IdentityHashMap();
}
return optimizedClonedExpressions;
}
/**
* INTERNAL:
* It is used by subqueries to avoid duplicate joins.
*/
public void addOptimizedClonedExpressions(Expression originalKey, Expression optimizedValue) {
// Lazily Initialized only to be used by subqueries.
if (optimizedClonedExpressions == null) {
optimizedClonedExpressions = new IdentityHashMap();
}
optimizedClonedExpressions.put(originalKey, optimizedValue);
}
/**
* INTERNAL:
* Computes all aliases which will appear in the FROM clause.
*/
public void computeTables() {
// Compute tables should never defer to computeTablesFromTables
// This iterator will pull all the table aliases out of an expression, and
// put them in a map.
ExpressionIterator iterator = new ExpressionIterator() {
@Override
public void iterate(Expression each) {
TableAliasLookup aliases = each.getTableAliases();
if (aliases != null) {
// Insure that an aliased table is only added to a single
// FROM clause.
if (!aliases.haveBeenAddedToStatement()) {
aliases.addToMap((Map)getResult());
aliases.setHaveBeenAddedToStatement(true);
}
}
}
};
iterator.setResult(new Hashtable(5));
if (getWhereClause() != null) {
iterator.iterateOn(getWhereClause());
} else if (hasOuterJoinExpressions()) {
Expression outerJoinCriteria = getOuterJoinExpressionsHolders().get(0).joinExpression;
if (outerJoinCriteria != null){
iterator.iterateOn(outerJoinCriteria);
}
}
//Iterate on fields as well in that rare case where the select is not in the where clause
for (Object field : getFields()) {
if (field instanceof Expression) {
iterator.iterateOn((Expression)field);
}
}
//Iterate on non-selected fields as well in that rare case where the from is not in the where clause
if (hasNonSelectFields()) {
for (Object field : getNonSelectFields()) {
if (field instanceof Expression) {
iterator.iterateOn((Expression)field);
}
}
}
// Always iterator on the builder, as the where clause may not contain the builder, i.e. value=value.
iterator.iterateOn(getBuilder());
Map allTables = (Map)iterator.getResult();
setTableAliases(allTables);
for (DatabaseTable table : allTables.values()) {
addTable(table);
}
}
/**
* If there is no where clause, alias the tables from the tables list directly. Assume there's
* no ambiguity
*/
public void computeTablesFromTables() {
Map allTables = new Hashtable();
AsOfClause asOfClause = null;
if (getBuilder().hasAsOfClause() && !getBuilder().getSession().getProject().hasGenericHistorySupport()) {
asOfClause = getBuilder().getAsOfClause();
}
for (int index = 0; index < getTables().size(); index++) {
DatabaseTable next = getTables().get(index);
// Aliases in allTables must now be decorated database tables.
DatabaseTable alias = new DecoratedDatabaseTable("t" + (index), asOfClause);
allTables.put(alias, next);
}
setTableAliases(allTables);
}
/**
* ADVANCED:
* If a distinct has been set the DISTINCT clause will be printed.
* This is used internally by TopLink for batch reading but may also be
* used directly for advanced queries or report queries.
*/
public void dontUseDistinct() {
setDistinctState(ObjectLevelReadQuery.DONT_USE_DISTINCT);
}
/**
* Check if the field from the field expression is already contained in the select clause of the statement.
* This is used on order by expression when the field being ordered by must be in the select,
* but cannot be in the select twice.
*/
protected boolean fieldsContainField(List fields, Expression expression) {
DatabaseField orderByField;
if (expression instanceof DataExpression) {
orderByField = ((DataExpression)expression).getField();
} else {
return false;
}
//check all fields for a match
for (Object fieldOrExpression : fields) {
if (fieldOrExpression instanceof DatabaseField) {
DatabaseField field = (DatabaseField)fieldOrExpression;
DataExpression exp = (DataExpression)expression;
if (field.equals(orderByField)) {
// Ignore aggregates
while (((DataExpression)exp.getBaseExpression()).getMapping() instanceof AggregateObjectMapping) {
exp = (DataExpression)exp.getBaseExpression();
}
if (exp.getBaseExpression() == getBuilder()) {
// found a match
return true;
}
}
}
// For CR#2589. This method was not getting the fields in the same way that
// printSQL does (i.e. using getFields() instead of getField()).
// The problem was that getField() on an expression builder led to a null pointer
// exception.
else if (fieldOrExpression != null){
Expression exp = (Expression)fieldOrExpression;
DatabaseTable table = orderByField.getTable();
if (exp.getFields().contains(orderByField) && (expression.aliasForTable(table).equals(exp.aliasForTable(table)))) {
//found a match
return true;
}
}
}
// no matches
return false;
}
/**
* Gets a unique id that will be used to alias the next table.
* For sub-selects all must use this same aliasing information, maintained
* in the root enclosing statement. For CR#2627019
*/
public int getCurrentAliasNumber() {
if (getParentStatement() != null) {
return getParentStatement().getCurrentAliasNumber();
} else {
return currentAliasNumber;
}
}
/**
* INTERNAL:
* Return all the fields
*/
public Vector getFields() {
return fields;
}
protected ForUpdateClause getForUpdateClause() {
return forUpdateClause;
}
/**
* INTERNAL:
* Return the group bys.
*/
public List getGroupByExpressions() {
if (groupByExpressions == null) {
groupByExpressions = new ArrayList();
}
return groupByExpressions;
}
/**
* INTERNAL:
* Return the having expression.
*/
public Expression getHavingExpression() {
return havingExpression;
}
/**
* INTERNAL:
* Query held as it may store properties needed to generate the SQL
*/
public ReadQuery getQuery() {
return this.query;
}
/**
* INTERNAL:
* Return the StartWith expression
*/
public Expression getStartWithExpression() {
return startWithExpression;
}
/**
* INTERNAL:
* Return the CONNECT BY expression
*/
public Expression getConnectByExpression() {
return connectByExpression;
}
/**
* INTERNAL:
* Return the ORDER SIBLINGS BY expression
*/
public List getOrderSiblingsByExpressions() {
return orderSiblingsByExpressions;
}
/**
* INTERNAL:
* @return the position of the PRIOR keyword
*/
public ReadAllQuery.Direction getDirection() {
return direction;
}
/**
* INTERNAL:
* Return the next value of fieldCounter
*/
public int getNextFieldCounterValue(){
return ++fieldCounter;
}
/**
* Return the fields we don't want to select but want to join on.
*/
public List getNonSelectFields() {
return nonSelectFields;
}
/**
* INTERNAL:
* Return the order expressions for the query.
*/
public List getOrderByExpressions() {
if (orderByExpressions == null) {
orderByExpressions = new ArrayList(4);
}
return orderByExpressions;
}
public List getUnionExpressions() {
if (unionExpressions == null) {
unionExpressions = new ArrayList(4);
}
return unionExpressions;
}
public void setUnionExpressions(List unionExpressions) {
this.unionExpressions = unionExpressions;
}
/**
* INTERNAL:
* returns outerJoinExpressionHolders representing outerjoin expressions.
* @return
*/
public List getOuterJoinExpressionsHolders() {
if (outerJoinExpressionHolders == null) {
outerJoinExpressionHolders = new ArrayList(4);
}
return outerJoinExpressionHolders;
}
/**
* INTERNAL:
* Used by ExpressionBuilder and QueryKeyExpression normalization to create a standard outerjoin.
* @param joinExpression - expression resulting in the outerjoin. Null if it is for inheritance reading of subclasses
* @param outerJoinedMappingCriteria - used for querykey mapping expressions
* @param outerJoinedAdditionalJoinCriteria - additional tables/expressions to join. Usually for multitableInheritance join expressions
* @param descriptor - descriptor to use if this is for reading in subclasses in one query.
* @return
*/
public Integer addOuterJoinExpressionsHolders(ObjectExpression joinExpression, Expression outerJoinedMappingCriteria,
Map outerJoinedAdditionalJoinCriteria, ClassDescriptor descriptor) {
int index = getOuterJoinExpressionsHolders().size();
OuterJoinExpressionHolder holder = new OuterJoinExpressionHolder(this, joinExpression, outerJoinedMappingCriteria,
outerJoinedAdditionalJoinCriteria, descriptor);
getOuterJoinExpressionsHolders().add(holder);
return index;
}
/**
* INTERNAL:
* used by TREAT to add in a join from the parent table to the child tables when
* the parent expression did not add an outer join of its own
*/
public Integer addOuterJoinExpressionsHolders(Map outerJoinedAdditionalJoinCriteria, ClassDescriptor descriptor) {
List outerJoinExpressionHolders = getOuterJoinExpressionsHolders();
int index = outerJoinExpressionHolders.size();
OuterJoinExpressionHolder holder = new OuterJoinExpressionHolder(this, null, null,
outerJoinedAdditionalJoinCriteria, descriptor) {
@Override
protected void process(boolean usesHistory, boolean isMapKeyHolder) {
sourceTable = descriptor.getTables().get(0);
int count = 0;
for (Map.Entry entry: outerJoinedAdditionalJoinCriteria.entrySet()) {
DatabaseTable table = entry.getKey();
Expression onExpression = entry.getValue();
if (count==0) {
targetTable = table;
sourceAlias = onExpression.aliasForTable(sourceTable);
targetAlias = onExpression.aliasForTable(targetTable);
}
if (onExpression != null) {
DatabaseTable alias = onExpression.aliasForTable(table);
if (usesHistory) {
table = getTableAliases().get(alias);
}
if (this.additionalTargetAliases == null) {
this.additionalTargetAliases = new ArrayList();
this.additionalTargetTables = new ArrayList();
this.additionalJoinOnExpression = new ArrayList();
this.additionalTargetIsDescriptorTable = new ArrayList();
}
this.additionalTargetAliases.add(alias);
this.additionalTargetTables.add(table);
this.additionalJoinOnExpression.add(onExpression);
// if it's descriptor's own table - true; otherwise (it's child's table) - false.
this.additionalTargetIsDescriptorTable.add(false);
}
count++;
}
if(usesHistory) {
sourceTable = getTableAliases().get(sourceAlias);
targetTable = getTableAliases().get(targetAlias);
}
}
};
outerJoinExpressionHolders.add(holder);
return index;
}
/**
* Return the parent statement if using subselects.
* This is used to normalize correctly with subselects.
*/
public SQLSelectStatement getParentStatement() {
return parentStatement;
}
/**
* INTERNAL:
* Return the aliases used.
*/
public Map getTableAliases() {
return tableAliases;
}
/**
* INTERNAL:
* Return all the tables.
*/
public List getTables() {
return tables;
}
/**
* INTERNAL:
* Return True if unique field aliases will be generated of the form
* "fieldname AS fieldnameX", False otherwise.
*/
public boolean getUseUniqueFieldAliases(){
return this.useUniqueFieldAliases;
}
protected boolean hasAliasForTable(DatabaseTable table) {
if (tableAliases != null) {
return getTableAliases().containsKey(table);
}
return false;
}
public boolean hasGroupByExpressions() {
return (groupByExpressions != null) && (!groupByExpressions.isEmpty());
}
public boolean hasHavingExpression() {
return (havingExpression != null);
}
public boolean hasStartWithExpression() {
return startWithExpression != null;
}
public boolean hasConnectByExpression() {
return connectByExpression != null;
}
public boolean hasOrderSiblingsByExpressions() {
return (orderSiblingsByExpressions != null) && (!orderSiblingsByExpressions.isEmpty());
}
public boolean hasHierarchicalQueryExpressions() {
return ((startWithExpression != null) || (connectByExpression != null) || ((orderSiblingsByExpressions != null) && (!orderSiblingsByExpressions.isEmpty())));
}
public boolean hasOrderByExpressions() {
return (orderByExpressions != null) && (!orderByExpressions.isEmpty());
}
public boolean hasUnionExpressions() {
return (unionExpressions != null) && (!unionExpressions.isEmpty());
}
public boolean hasNonSelectFields() {
return (nonSelectFields != null) && (!nonSelectFields.isEmpty());
}
public boolean hasOuterJoinExpressions() {
return (outerJoinExpressionHolders != null) && (!outerJoinExpressionHolders.isEmpty());
}
/**
* INTERNAL:
*/
public boolean isAggregateSelect() {
return isAggregateSelect;
}
/**
* INTERNAL:
* return true if this query has computed its distinct value already
*/
public boolean isDistinctComputed() {
return distinctState != ObjectLevelReadQuery.UNCOMPUTED_DISTINCT;
}
/**
* INTERNAL:
* Normalize an expression into a printable structure.
* i.e. merge the expression with the join expressions.
* Also replace table names with corresponding aliases.
*/
public final void normalize(AbstractSession session, ClassDescriptor descriptor) {
// 2612538 - the default size of Map (32) is appropriate
normalize(session, descriptor, new IdentityHashMap());
}
/**
* INTERNAL:
* Normalize an expression into a printable structure.
* i.e. merge the expression with the join expressions.
* Also replace table names with corresponding aliases.
* @param clonedExpressions With 2612185 allows additional expressions
* from multiple bases to be rebuilt on the correct cloned base.
*/
public void normalize(AbstractSession session, ClassDescriptor descriptor, Map clonedExpressions) {
// Initialize the builder.
if (getBuilder() == null) {
if (getWhereClause() == null) {
setBuilder(new ExpressionBuilder());
} else {
setBuilder(getWhereClause().getBuilder());
}
}
ExpressionBuilder builder = getBuilder();
// For flashback at this point make the expression
// as of the correct time.
if ((session.getAsOfClause() != null) && !isSubSelect()) {
getWhereClause().asOf(session.getAsOfClause());
} else if (builder.hasAsOfClause() && builder.getAsOfClause().isUniversal()) {
// An as of clause set at the query level.
getWhereClause().asOf(((UniversalAsOfClause)builder.getAsOfClause()).getAsOfClause());
}
// For flashback: The builder is increasingly important. It can store
// an AsOfClause, needs to be normalized for history, and aliased for
// pessimistic locking to work. Hence everything that would have
// been applied to the where clause will be applied to the builder if
// the former is null. In the past though if there was no where
// clause just threw away the builder (to get to this point we had to
// pass it in via the vacated where clause), and neither normalized nor
// aliased it directly.
if (getWhereClause() == builder) {
setWhereClause(null);
}
builder.setSession(session.getRootSession(null));
// Some queries are not on objects but for data, thus no descriptor.
if (!builder.doesNotRepresentAnObjectInTheQuery()) {
if (descriptor != null) {
Class queryClass = builder.getQueryClass();
// GF 2333 Only change the descriptor class if:
// 1 - it is not set
// 2 - if this is an inheritance query
// 3 - if it is to a table per tenant multitenant descriptor.
// When used at the EM level we need to ensure we are
// normalizing against the initialized descriptor and not
// that of the server session which is uninitialized.
if ((queryClass == null) || descriptor.isChildDescriptor() || descriptor.hasTablePerMultitenantPolicy()) {
builder.setQueryClassAndDescriptor(descriptor.getJavaClass(), descriptor);
}
}
}
// Compute all other expressions used other than the where clause, i.e. select, order by, group by.
// Also must ensure that all expression use a unique builder.
Vector allExpressions = new Vector();
// Process select expressions.
rebuildAndAddExpressions(getFields(), allExpressions, builder, clonedExpressions);
// Process non-select expressions
if (hasNonSelectFields()) {
rebuildAndAddExpressions(getNonSelectFields(), allExpressions, builder, clonedExpressions);
}
// Process group by expressions.
if (hasGroupByExpressions()) {
rebuildAndAddExpressions(getGroupByExpressions(), allExpressions, builder, clonedExpressions);
}
// Process union expressions.
if (hasUnionExpressions()) {
rebuildAndAddExpressions(getUnionExpressions(), allExpressions, builder, clonedExpressions);
}
if (hasHavingExpression()) {
//rebuildAndAddExpressions(getHavingExpression(), allExpressions, builder, clonedExpressions);
Expression expression = getHavingExpression();
ExpressionBuilder originalBuilder = expression.getBuilder();
if (originalBuilder != builder) {
// For bug 2612185 avoid rebuildOn if possible as it rebuilds all on a single base.
// i.e. Report query items could be from parallel expressions.
if (clonedExpressions.get(originalBuilder) != null) {
expression = expression.copiedVersionFrom(clonedExpressions);
} else {
// Possibly the expression was built with the wrong builder.
expression = expression.rebuildOn(builder);
}
setHavingExpression(expression);
}
allExpressions.add(expression);
}
// Process order by expressions.
if (hasOrderByExpressions()) {
normalizeOrderBy(builder, allExpressions, clonedExpressions, session);
}
// Process outer join by expressions.
if (hasOuterJoinExpressions()) {
for (OuterJoinExpressionHolder holder : this.getOuterJoinExpressionsHolders()) {
if (holder.outerJoinedMappingCriteria != null) {
Expression expression = rebuildExpression(holder.outerJoinedMappingCriteria, builder, clonedExpressions);
if (holder.outerJoinedMappingCriteria != expression) {
holder.outerJoinedMappingCriteria = expression;
}
allExpressions.add(expression);
}
if (holder.outerJoinedAdditionalJoinCriteria != null) {
rebuildAndAddExpressions(holder.outerJoinedAdditionalJoinCriteria, allExpressions, builder, clonedExpressions);
}
}
}
//Process hierarchical query expressions.
if (hasStartWithExpression()) {
startWithExpression = getStartWithExpression().rebuildOn(builder);
allExpressions.add(startWithExpression);
}
if (hasConnectByExpression()) {
connectByExpression = getConnectByExpression().rebuildOn(builder);
}
if (hasOrderSiblingsByExpressions()) {
rebuildAndAddExpressions(getOrderSiblingsByExpressions(), allExpressions, builder, clonedExpressions);
}
// We have to handle the cases where the where
// clause is initially empty but might have clauses forced into it because the class
// has multiple tables, order by forces a join, etc. So we have to create a builder
// and add expressions for it and the extras, but throw it away if they didn't force anything
Expression oldRoot = getWhereClause();
ExpressionNormalizer normalizer = new ExpressionNormalizer(this);
normalizer.setSession(session);
normalizer.setClonedExpressions(clonedExpressions);
boolean isDistinctComputed = isDistinctComputed();
Expression newRoot = null;
if (oldRoot != null) {
newRoot = oldRoot.normalize(normalizer);
}
// CR#3166542 always ensure that the builder has been normalized,
// there may be an expression that does not refer to the builder, i.e. value=value.
if (descriptor != null) {
builder.normalize(normalizer);
}
for (int index = 0; index < allExpressions.size(); index++) {
Expression expression = (Expression)allExpressions.get(index);
expression.getBuilder().setSession(session);
expression.normalize(normalizer);
}
// distinct state has been set by normalization, see may be that should be reversed
if (shouldDistinctBeUsed() && !isDistinctComputed && !session.getPlatform().isLobCompatibleWithDistinct()) {
for (Object field : getFields()) {
if (field instanceof DatabaseField) {
if (Helper.isLob((DatabaseField)field)) {
dontUseDistinct();
break;
}
} else if (field instanceof Expression) {
if (Helper.hasLob(((Expression)field).getSelectionFields(this.query))) {
dontUseDistinct();
break;
}
}
}
}
// Sets the where clause and AND's it with the additional Expression
// setNormalizedWhereClause must be called to avoid the builder side-effects
if (newRoot == null) {
setNormalizedWhereClause(normalizer.getAdditionalExpression());
} else {
setNormalizedWhereClause(newRoot.and(normalizer.getAdditionalExpression()));
}
if (getWhereClause() != null) {
allExpressions.add(getWhereClause());
}
// CR#3166542 always ensure that the builder has been normalized,
// there may be an expression that does not refer to the builder, i.e. value=value.
if (descriptor != null) {
allExpressions.add(builder);
}
// Must also assign aliases to outer joined mapping criterias.
if (hasOuterJoinExpressions()) {
// Check for null on criterias.
for (OuterJoinExpressionHolder holder : this.outerJoinExpressionHolders) {
Expression criteria = holder.outerJoinedMappingCriteria;//
if (criteria != null) {
allExpressions.add(criteria);
}
Map map = holder.outerJoinedAdditionalJoinCriteria;
if (map != null) {
Iterator it = map.values().iterator();
while(it.hasNext()) {
criteria = (Expression)it.next();
if(criteria != null) {
allExpressions.add(criteria);
}
}
}
}
}
// Bug 2956674 Remove validate call as validation will be completed as the expression was normalized
// Assign all table aliases.
assignAliases(allExpressions);
// If this is data level then the tables must be set manually.
if (descriptor == null) {
computeTablesFromTables();
} else {
computeTables();
}
// Now that the parent statement has been normalized, aliased, etc.,
// normalize the subselect expressions. For CR#4223.
if (normalizer.encounteredSubSelectExpressions()) {
normalizer.normalizeSubSelects(clonedExpressions);
}
// When a distinct is used the order bys must be in the select clause, so this forces them into the select.
if (hasOrderByExpressions()) {
// CR2114; If this is data level then we don't have a descriptor.
// We don't have a target class so we must use the root platform. PWK
// We are not fixing the informix.
Class queryClass = null;
if (descriptor != null) {
queryClass = descriptor.getJavaClass();
}
DatasourcePlatform platform = (DatasourcePlatform)session.getPlatform(queryClass);
if (platform.shouldSelectIncludeOrderBy() || (shouldDistinctBeUsed() && platform.shouldSelectDistinctIncludeOrderBy())) {
addOrderByExpressionToSelectForDistinct();
}
}
}
/**
* INTERNAL:
* Normalize an expression mapping all of the descriptor's tables to the view.
* This is used to allow a descriptor to read from a view, but write to tables.
* This is used in the multiple table and subclasses read so all of the descriptor's
* possible tables must be mapped to the view.
*/
public void normalizeForView(AbstractSession theSession, ClassDescriptor theDescriptor, Map clonedExpressions) {
ExpressionBuilder builder;
// bug 3878553 - alias all view selects.
setRequiresAliases(true);
if (getWhereClause() != null) {
builder = getWhereClause().getBuilder();
} else {
builder = new ExpressionBuilder();
setBuilder(builder);
}
builder.setViewTable(getTables().get(0));
normalize(theSession, theDescriptor, clonedExpressions);
}
/**
* Check the order by for object expressions.
* Order by the objects primary key or all fields for aggregates.
*/
protected void normalizeOrderBy(Expression builder, List allExpressions, Map clonedExpressions, AbstractSession session) {
List newOrderBys = new ArrayList(this.orderByExpressions.size());
for (Expression orderBy : this.orderByExpressions) {
orderBy = rebuildExpression(orderBy, builder, clonedExpressions);
Expression base = orderBy;
Boolean asc = null;
Boolean nullsFirst = null;
if (orderBy.isFunctionExpression()) {
if (base.getOperator().getSelector() == ExpressionOperator.NullsFirst) {
nullsFirst = true;
base = ((FunctionExpression)base).getChildren().get(0);
} else if (base.getOperator().getSelector() == ExpressionOperator.NullsLast) {
nullsFirst = false;
base = ((FunctionExpression)base).getChildren().get(0);
}
if (base.isFunctionExpression()) {
if (base.getOperator().getSelector() == ExpressionOperator.Ascending) {
asc = true;
base = ((FunctionExpression)base).getChildren().get(0);
} else if (base.getOperator().getSelector() == ExpressionOperator.Descending) {
asc = false;
base = ((FunctionExpression)base).getChildren().get(0);
}
}
}
if (base.isObjectExpression()) {
ObjectExpression expression = (ObjectExpression)base;
expression.getBuilder().setSession(session);
List orderBys = null;
if (expression.getMapping() != null) {
// Check if a non basic mapping.
orderBys = expression.getMapping().getOrderByNormalizedExpressions(expression);
} else if (base.isExpressionBuilder()) {
orderBys = new ArrayList(expression.getDescriptor().getPrimaryKeyFields().size());
for (DatabaseField field : expression.getDescriptor().getPrimaryKeyFields()) {
orderBys.add(expression.getField(field));
}
}
if (orderBys != null) {
for (Expression mappingOrderBy : orderBys) {
if (asc != null) {
if (asc) {
mappingOrderBy = mappingOrderBy.ascending();
} else {
mappingOrderBy = mappingOrderBy.descending();
}
}
if (nullsFirst != null) {
if (nullsFirst) {
mappingOrderBy = mappingOrderBy.nullsFirst();
} else {
mappingOrderBy = mappingOrderBy.nullsLast();
}
}
newOrderBys.add(mappingOrderBy);
allExpressions.add(mappingOrderBy);
}
continue;
}
}
newOrderBys.add(orderBy);
allExpressions.add(orderBy);
}
this.orderByExpressions = newOrderBys;
}
/**
* Print the SQL representation of the statement on a stream.
*/
public Vector printSQL(ExpressionSQLPrinter printer) {
try {
Vector selectFields = null;
printer.setRequiresDistinct(shouldDistinctBeUsed());
if (hasUnionExpressions()) {
// Ensure union order using brackets.
int size = getUnionExpressions().size();
for (int index = 0; index < size; index++) {
printer.printString("(");
}
}
printer.printString("SELECT ");
if (getHintString() != null) {
printer.printString(getHintString());
printer.printString(" ");
}
if (shouldDistinctBeUsed()) {
printer.printString("DISTINCT ");
}
selectFields = writeFieldsIn(printer);
//fix bug:6070214: turn off unique field aliases after fields are written
setUseUniqueFieldAliases(false);
appendFromClauseToWriter(printer);
if (!(getWhereClause() == null)) {
printer.printString(" WHERE ");
printer.printExpression(getWhereClause());
}
if (hasHierarchicalQueryExpressions()) {
appendHierarchicalQueryClauseToWriter(printer);
}
if (hasGroupByExpressions()) {
appendGroupByClauseToWriter(printer);
}
if (hasHavingExpression()) {
//appendHavingClauseToWriter(printer);
printer.printString(" HAVING ");
printer.printExpression(getHavingExpression());
}
if (hasOrderByExpressions()) {
appendOrderClauseToWriter(printer);
}
if(printer.getPlatform().shouldPrintLockingClauseAfterWhereClause() && printer.getPlatform().shouldPrintForUpdateClause()) {
// For pessimistic locking.
appendForUpdateClause(printer);
}
if (hasUnionExpressions()) {
appendUnionClauseToWriter(printer);
}
return selectFields;
} catch (IOException exception) {
throw ValidationException.fileError(exception);
}
}
/**
* Rebuild the expressions with the correct expression builder if using a different one.
*/
public void rebuildAndAddExpressions(List expressions, List allExpressions, ExpressionBuilder primaryBuilder, Map clonedExpressions) {
for (int index = 0; index < expressions.size(); index++) {
Object fieldOrExpression = expressions.get(index);
// Allow for special fields that contain a functional transformation.
if (fieldOrExpression instanceof FunctionField) {
fieldOrExpression = ((FunctionField)fieldOrExpression).getExpression();
}
if (fieldOrExpression instanceof Expression) {
Expression expression = rebuildExpression((Expression)fieldOrExpression, primaryBuilder, clonedExpressions);
if (fieldOrExpression != expression) {
expressions.set(index, expression);
}
allExpressions.add(expression);
}
}
}
/**
* Rebuild the expression if required.
*/
public Expression rebuildExpression(Expression expression, Expression primaryBuilder, Map clonedExpressions) {
ExpressionBuilder originalBuilder = expression.getBuilder();
if (originalBuilder != primaryBuilder) {
// For bug 2612185 avoid rebuildOn if possible as it rebuilds all on a single base.
// i.e. Report query items could be from parallel expressions.
if (clonedExpressions.get(originalBuilder) != null) {
expression = expression.copiedVersionFrom(clonedExpressions);
//if there is no builder or it is a copy of the base builder then rebuild otherwise it is a parallel expression not joined
}
if (originalBuilder.wasQueryClassSetInternally()) {
// Possibly the expression was built with the wrong builder.
expression = expression.rebuildOn(primaryBuilder);
}
}
return expression;
}
/**
* Rebuild the expressions with the correct expression builder if using a different one.
* Exact copy of the another rebuildAndAddExpressions adopted to a Map with Expression values
* as the first parameter (instead of Vector in the original method)
*/
public void rebuildAndAddExpressions(Map expressions, Vector allExpressions, ExpressionBuilder primaryBuilder, Map clonedExpressions) {
Iterator it = expressions.entrySet().iterator();
while (it.hasNext()) {
Map.Entry entry = (Map.Entry)it.next();
Object fieldOrExpression = entry.getValue();
if (fieldOrExpression instanceof Expression) {
Expression expression = (Expression)fieldOrExpression;
ExpressionBuilder originalBuilder = expression.getBuilder();
if (originalBuilder != primaryBuilder) {
// For bug 2612185 avoid rebuildOn if possible as it rebuilds all on a single base.
// i.e. Report query items could be from parallel expressions.
if (clonedExpressions.get(originalBuilder) != null) {
expression = expression.copiedVersionFrom(clonedExpressions);
//if there is no builder or it is a copy of the base builder then rebuild otherwise it is a parallel expression not joined
}
if (originalBuilder.wasQueryClassSetInternally()) {
// Possibly the expression was built with the wrong builder.
expression = expression.rebuildOn(primaryBuilder);
}
entry.setValue(expression);
}
allExpressions.addElement(expression);
}
}
}
/**
* INTERNAL:
*/
public void removeField(DatabaseField field) {
getFields().remove(field);
}
/**
* Remove a table from the statement. The table will
* be dropped from the FROM part of the SQL statement.
*/
public void removeTable(DatabaseTable table) {
getTables().remove(table);
}
/**
* INTERNAL: Returns true if aliases are required, false otherwise.
* If requiresAliases is set then force aliasing, this is required for object-rel.
*/
public boolean requiresAliases() {
if (requiresAliases || hasOuterJoinExpressions()) {
return true;
}
if (tableAliases != null) {
return getTableAliases().size() > 1;
}
// tableAliases is null
return false;
}
/**
* ADVANCED:
* If a distinct has been set the DISTINCT clause will be printed.
* This is used internally by TopLink for batch reading but may also be
* used directly for advanced queries or report queries.
*/
public void resetDistinct() {
setDistinctState(ObjectLevelReadQuery.UNCOMPUTED_DISTINCT);
}
@Override
public void setBuilder(ExpressionBuilder builder){
this.builder = builder;
}
/**
* Sets a unique id that will be used to alias the next table.
* For sub-selects all must use this same aliasing information, maintained
* in the root enclosing statement. For CR#2627019
*/
public void setCurrentAliasNumber(int currentAliasNumber) {
if (getParentStatement() != null) {
getParentStatement().setCurrentAliasNumber(currentAliasNumber);
} else {
this.currentAliasNumber = currentAliasNumber;
}
}
/**
* Set the non select fields. The fields are used only on joining.
*/
public void setNonSelectFields(List nonSelectFields) {
this.nonSelectFields = nonSelectFields;
}
/**
* Set the where clause expression.
* This must be used during normalization as the normal setWhereClause has the side effect
* of setting the builder, which must not occur during normalize.
*/
public void setNormalizedWhereClause(Expression whereClause) {
this.whereClause = whereClause;
}
/**
* ADVANCED:
* If a distinct has been set the DISTINCT clause will be printed.
* This is used internally by TopLink for batch reading but may also be
* used directly for advanced queries or report queries.
*/
public void setDistinctState(short distinctState) {
this.distinctState = distinctState;
}
/**
* INTERNAL:
* Set the fields, if any are aggregate selects then record this so that the distinct is not printed through anyOfs.
*/
public void setFields(Vector fields) {
for (Object fieldOrExpression : fields) {
if (fieldOrExpression instanceof FunctionExpression) {
if (((FunctionExpression)fieldOrExpression).getOperator().isAggregateOperator()) {
setIsAggregateSelect(true);
break;
}
}
}
this.fields = fields;
}
public void setGroupByExpressions(List expressions) {
this.groupByExpressions = expressions;
}
public void setHavingExpression(Expression expressions) {
this.havingExpression = expressions;
}
/**
* INTERNAL:
* takes the hierarchical query expression which have been set on the query and sets them here
* used to generate the Hierarchical Query Clause in the SQL
*/
public void setHierarchicalQueryExpressions(Expression startWith, Expression connectBy, List orderSiblingsExpressions) {
setHierarchicalQueryExpressions(startWith, connectBy, orderSiblingsExpressions, null);
}
/**
* INTERNAL:
* takes the hierarchical query expression which have been set on the query and sets them here
* used to generate the Hierarchical Query Clause in the SQL
*/
public void setHierarchicalQueryExpressions(Expression startWith, Expression connectBy, List orderSiblingsExpressions, ReadAllQuery.Direction direction) {
this.startWithExpression = startWith;
this.connectByExpression = connectBy;
this.orderSiblingsByExpressions = orderSiblingsExpressions;
this.direction = direction;
}
public void setIsAggregateSelect(boolean isAggregateSelect) {
this.isAggregateSelect = isAggregateSelect;
}
protected void setForUpdateClause(ForUpdateClause clause) {
this.forUpdateClause = clause;
}
public void setLockingClause(ForUpdateClause lockingClause) {
this.forUpdateClause = lockingClause;
}
public void setOrderByExpressions(List orderByExpressions) {
this.orderByExpressions = orderByExpressions;
}
/**
* Set the parent statement if using subselects.
* This is used to normalize correctly with subselects.
*/
public void setParentStatement(SQLSelectStatement parentStatement) {
this.parentStatement = parentStatement;
}
/**
* Query held as it may store properties needed to generate the SQL
*/
public void setQuery(ReadQuery query) {
this.query = query;
}
public void setRequiresAliases(boolean requiresAliases) {
this.requiresAliases = requiresAliases;
}
protected void setTableAliases(Map theTableAliases) {
tableAliases = theTableAliases;
}
public void setTables(List theTables) {
tables = theTables;
}
/**
* INTERNAL:
* If set unique field aliases will be generated of the form
* "fieldname AS fieldnameX"
* Where fieldname is the column name and X is an incremental value
* ensuring uniqueness
*/
public void setUseUniqueFieldAliases(boolean useUniqueFieldAliases){
this.useUniqueFieldAliases = useUniqueFieldAliases;
}
/**
* INTERNAL:
* If a distinct has been set the DISTINCT clause will be printed.
* This is required for batch reading.
*/
public boolean shouldDistinctBeUsed() {
return distinctState == ObjectLevelReadQuery.USE_DISTINCT;
}
/**
* ADVANCED:
* If a distinct has been set the DISTINCT clause will be printed.
* This is used internally by TopLink for batch reading but may also be
* used directly for advanced queries or report queries.
*/
public void useDistinct() {
setDistinctState(ObjectLevelReadQuery.USE_DISTINCT);
}
/**
* INTERNAL:
*/
protected void writeField(ExpressionSQLPrinter printer, DatabaseField field) {
//print ", " before each selected field except the first one
if (printer.isFirstElementPrinted()) {
printer.printString(", ");
} else {
printer.setIsFirstElementPrinted(true);
}
if (printer.shouldPrintQualifiedNames()) {
if (field.getTable() != lastTable) {
lastTable = field.getTable();
currentAlias = getBuilder().aliasForTable(lastTable);
// This is really for the special case where things were pre-aliased
if (currentAlias == null) {
currentAlias = lastTable;
}
}
printer.printString(currentAlias.getQualifiedNameDelimited(printer.getPlatform()));
printer.printString(".");
printer.printString(field.getNameDelimited(printer.getPlatform()));
} else {
printer.printString(field.getNameDelimited(printer.getPlatform()));
}
if (this.getUseUniqueFieldAliases()){
String alias = generatedAlias(field.getNameDelimited(printer.getPlatform()));
if (shouldCacheFieldAliases()) {
fieldAliases.put(field, alias);
}
printer.printString(" AS " + alias);
}
}
private boolean shouldCacheFieldAliases() {
return shouldCacheFieldAliases;
}
public void enableFieldAliasesCaching() {
fieldAliases = new HashMap<>();
shouldCacheFieldAliases = true;
}
public String getAliasFor(DatabaseField field) {
if (shouldCacheFieldAliases()) {
return fieldAliases.get(field);
} else {
return "";
}
}
/**
* Returns a generated alias based on the column name. If the new alias will be too long
* The alias is automatically truncated
*/
public String generatedAlias(String fieldName) {
return "a" + String.valueOf(getNextFieldCounterValue());
}
/**
* INTERNAL:
*/
protected void writeFieldsFromExpression(ExpressionSQLPrinter printer, Expression expression, Vector newFields) {
expression.writeFields(printer, newFields, this);
}
/**
* INTERNAL:
*/
protected Vector writeFieldsIn(ExpressionSQLPrinter printer) {
this.lastTable = null;
Vector newFields = NonSynchronizedVector.newInstance();
for (Object next : getFields()) {
// Fields can be null placeholders for fetch groups.
if (next != null) {
if (next instanceof Expression) {
writeFieldsFromExpression(printer, (Expression)next, newFields);
} else {
writeField(printer, (DatabaseField)next);
newFields.add(next);
}
}
}
return newFields;
}
/**
* INTERNAL:
* The method searches for expressions that join two tables each in a given expression.
* Given expression and tablesInOrder and an empty SortedMap (TreeMap with no Comparator), this method
* populates the map with expressions corresponding to two tables
* keyed by an index (in tablesInOrder) of the table with the highest (of two) index;
* returns all the participating in at least one of the expressions.
* Example:
* expression (joining Employee to Project through m-m mapping "projects"):
* (employee.emp_id = proj_emp.emp_id) and (proj_emp.proj_id = project.proj_id)
* tablesInOrder:
* employee, proj_emp, project
*
* results:
* map:
* 1 -> (employee.emp_id = proj_emp.emp_id)
* 2 -> (proj_emp.proj_id = project.proj_id)
* returned SortedSet: {0, 1, 2}.
*
* Note that tablesInOrder must contain all tables used by expression
*/
public static SortedSet mapTableIndexToExpression(Expression expression, TreeMap map, List tablesInOrder) {
// glassfish issue 2440:
// - Use DataExpression.getAliasedField instead of getField. This
// allows to distinguish source and target tables in case of a self
// referencing relationship.
// - Removed the block handling ParameterExpressions, because it is
// not possible to get into that method with a ParameterExpression.
TreeSet tables = new TreeSet();
if(expression instanceof DataExpression) {
DataExpression de = (DataExpression)expression;
if(de.getAliasedField() != null) {
tables.add(Integer.valueOf(tablesInOrder.indexOf(de.getAliasedField().getTable())));
}
return tables;
}
// Bug 279784 - Incomplete OUTER JOIN based on JoinTable.
// Save a copy of the original map to accommodate cases with more than one joined field, such as:
// (employee.emp_id1 = proj_emp.emp_id1).and((employee.emp_id2 = proj_emp.emp_id2).and((proj_emp.proj_id1 = project.proj_id1).and(proj_emp.proj_id2 = project.proj_id2)))
// Never adding (always overriding) cached expression (the code before the fix) resulted in the first child (employee.emp_id1 = proj_emp.emp_id1) being overridden and lost.
// Always adding to the cached in the map expression would result in (proj_emp.proj_id1 = project.proj_id1).and(proj_emp.proj_id2 = project.proj_id2)) added twice.
TreeMap originalMap = (TreeMap)map.clone();
if(expression instanceof CompoundExpression) {
CompoundExpression ce = (CompoundExpression)expression;
tables.addAll(mapTableIndexToExpression(ce.getFirstChild(), map, tablesInOrder));
tables.addAll(mapTableIndexToExpression(ce.getSecondChild(), map, tablesInOrder));
} else if(expression instanceof FunctionExpression) {
FunctionExpression fe = (FunctionExpression)expression;
Iterator it = fe.getChildren().iterator();
while(it.hasNext()) {
tables.addAll(mapTableIndexToExpression(it.next(), map, tablesInOrder));
}
}
if(tables.size() == 2) {
Object last = tables.last();
Expression cachedExpression = (Expression)originalMap.get(last);
if(cachedExpression == null) {
map.put(last, expression);
} else {
map.put(last, cachedExpression.and(expression));
}
}
return tables;
}
/**
* INTERNAL:
* The method searches for expressions that join two tables each in a given expression.
* Given expression and tablesInOrder, this method
* returns the map with expressions corresponding to two tables
* keyed by tables (from tablesInOrder) with the highest (of two) index;
* Example:
* expression (joining Employee to Project through m-m mapping "projects"):
* (employee.emp_id = proj_emp.emp_id) and (proj_emp.proj_id = project.proj_id)
* tablesInOrder:
* employee, proj_emp, project
*
* results:
* returned map:
* proj_emp -> (employee.emp_id = proj_emp.emp_id)
* project -> (proj_emp.proj_id = project.proj_id)
*
* Note that tablesInOrder must contain all tables used by expression
*/
public static Map mapTableToExpression(Expression expression, Vector tablesInOrder) {
TreeMap indexToExpressionMap = new TreeMap();
mapTableIndexToExpression(expression, indexToExpressionMap, tablesInOrder);
HashMap map = new HashMap(indexToExpressionMap.size());
Iterator it = indexToExpressionMap.entrySet().iterator();
while(it.hasNext()) {
Map.Entry entry = (Map.Entry)it.next();
int index = ((Integer)entry.getKey()).intValue();
map.put(tablesInOrder.get(index), entry.getValue());
}
return map;
}
// Outer join support methods / classes
/*
* Sort the holder list.
* The sorting of holders is done to make sure that
* for every table alias that is both source of (one or more) holders
* and target of another holder the "target" holder is listed
* before the "source" holder(s).
* Denoting a holder as a pair of source alias and target alias, that means:
*
* {t0, t1}, {t1, t2}, {t1, t3} or {t0, t1}, {t1, t3}, {t1, t2} is ok;
* but
* {t1, t2}, {t0, t1}, {t1, t3} or {t1, t2}, {t1, t3}, {t0, t1} should be reordered.
*
* To achieve this goal the method assigns an integer index to each table alias
* used by holders (for instance t0 -> 0; t1 -> 1; t2 -> 2; t3 -> 3).
*
* Each holder assigned a list of integers corresponding to a sequence of aliases
* that starts with the one, which no holder uses as its target alias,
* possibly continues several times from source alias to target alias for some other holder (if exists),
* and ends with the holder's target alias.
*
* {t0, t1} -> {0, 1};
* {t1, t2} -> {0, 1, 2}
* {t1, t3} -> {0, 1, 3}
*
* Sorting of holders uses comparison of these lists (see OuterJoinExpressionHolder.compareTo):
*
* {0, 1} < {0, 1, 2} < {0, 1, 3}
* Therefore the holders will be ordered:
* {t0, t1}, {t1, t2}, {t1, t3}
*
* More complex example:
* {t0, t1}, {t1, t2}, {t2, t7}, {t7, t10}, {t1, t3}, {t4, t5}, {t5, t8}, {t8, t9}, {t5, t11}, {t4, t12}
*
* A holder may have additional target table(s):
* Examples:
* secondary SALARY table in Employee class;
* LPROJECT table in LargeProject class (primary PROJECT table is inherited from Project class).
* In that case each additional target alias should have an entry in targetAliasToHolders
* so that the holder that uses the additional table as a source could be placed in correct order.
* For instance:
* holder1 has target alias t1 and additional target alias t2:
* if the latter is ignored then holder2 = {t2, t3} could be placed ahead of holder1.
*
*/
protected void sortOuterJoinExpressionHolders(List holders) {
Map targetAliasToHolders = new HashMap();
Set aliases = new HashSet();
Map aliasToIndexes = new HashMap(aliases.size());
int i = 0;
for(OuterJoinExpressionHolder holder : holders) {
targetAliasToHolders.put(holder.targetAlias, holder);
if(!aliases.contains(holder.sourceAlias)) {
aliases.add(holder.sourceAlias);
aliasToIndexes.put(holder.sourceAlias, i++);
}
if(!aliases.contains(holder.targetAlias)) {
aliases.add(holder.targetAlias);
aliasToIndexes.put(holder.targetAlias, i++);
}
if(holder.additionalTargetAliases != null) {
// if t1 is target alias and t2 is additional target alias (corresponding either to the secondary or inherited table)
for(DatabaseTable alias : holder.additionalTargetAliases) {
if(!aliases.contains(alias)) {
aliases.add(alias);
aliasToIndexes.put(alias, i++);
}
targetAliasToHolders.put(alias, holder);
}
}
}
for(OuterJoinExpressionHolder holder : holders) {
holder.createIndexList(targetAliasToHolders, aliasToIndexes);
}
Collections.sort(holders);
}
}
