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/*
* Copyright (c) 1998, 2024 Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1998, 2024 IBM 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
// Thomas Spiegl - fix for bug 324406
// 10/15/2010-2.2 Guy Pelletier
// - 322008: Improve usability of additional criteria applied to queries at the session/EM
// 05/10/2018-master Joe Grassel
// - Github#93: Bug with bulk update processing involving version field update parameter
// 10/01/2018: Will Dazey
// - #253: Add support for embedded constructor results with CriteriaBuilder
package org.eclipse.persistence.internal.queries;
import org.eclipse.persistence.descriptors.ClassDescriptor;
import org.eclipse.persistence.descriptors.DescriptorQueryManager;
import org.eclipse.persistence.descriptors.InheritancePolicy;
import org.eclipse.persistence.exceptions.DatabaseException;
import org.eclipse.persistence.exceptions.QueryException;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.expressions.ExpressionBuilder;
import org.eclipse.persistence.internal.databaseaccess.DatabaseCall;
import org.eclipse.persistence.internal.databaseaccess.DatasourceCall;
import org.eclipse.persistence.internal.databaseaccess.DatasourcePlatform;
import org.eclipse.persistence.internal.descriptors.OptimisticLockingPolicy;
import org.eclipse.persistence.internal.expressions.ConstantExpression;
import org.eclipse.persistence.internal.expressions.DataExpression;
import org.eclipse.persistence.internal.expressions.ExpressionIterator;
import org.eclipse.persistence.internal.expressions.FieldExpression;
import org.eclipse.persistence.internal.expressions.ObjectExpression;
import org.eclipse.persistence.internal.expressions.ParameterExpression;
import org.eclipse.persistence.internal.expressions.QueryKeyExpression;
import org.eclipse.persistence.internal.expressions.SQLDeleteAllStatement;
import org.eclipse.persistence.internal.expressions.SQLDeleteAllStatementForTempTable;
import org.eclipse.persistence.internal.expressions.SQLDeleteStatement;
import org.eclipse.persistence.internal.expressions.SQLInsertStatement;
import org.eclipse.persistence.internal.expressions.SQLModifyAllStatementForTempTable;
import org.eclipse.persistence.internal.expressions.SQLModifyStatement;
import org.eclipse.persistence.internal.expressions.SQLSelectStatement;
import org.eclipse.persistence.internal.expressions.SQLStatement;
import org.eclipse.persistence.internal.expressions.SQLUpdateAllStatement;
import org.eclipse.persistence.internal.expressions.SQLUpdateAllStatementForOracleAnonymousBlock;
import org.eclipse.persistence.internal.expressions.SQLUpdateAllStatementForTempTable;
import org.eclipse.persistence.internal.expressions.SQLUpdateStatement;
import org.eclipse.persistence.internal.helper.DatabaseField;
import org.eclipse.persistence.internal.helper.DatabaseTable;
import org.eclipse.persistence.internal.helper.InvalidObject;
import org.eclipse.persistence.internal.helper.NonSynchronizedVector;
import org.eclipse.persistence.internal.identitymaps.CacheKey;
import org.eclipse.persistence.internal.sessions.AbstractRecord;
import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.internal.sessions.UnitOfWorkImpl;
import org.eclipse.persistence.logging.SessionLog;
import org.eclipse.persistence.mappings.AggregateCollectionMapping;
import org.eclipse.persistence.mappings.DatabaseMapping;
import org.eclipse.persistence.mappings.DirectCollectionMapping;
import org.eclipse.persistence.mappings.ForeignReferenceMapping;
import org.eclipse.persistence.mappings.ManyToManyMapping;
import org.eclipse.persistence.mappings.OneToOneMapping;
import org.eclipse.persistence.mappings.RelationTableMechanism;
import org.eclipse.persistence.queries.ConstructorReportItem;
import org.eclipse.persistence.queries.DatabaseQuery;
import org.eclipse.persistence.queries.DeleteAllQuery;
import org.eclipse.persistence.queries.DeleteObjectQuery;
import org.eclipse.persistence.queries.FetchGroup;
import org.eclipse.persistence.queries.InMemoryQueryIndirectionPolicy;
import org.eclipse.persistence.queries.ModifyAllQuery;
import org.eclipse.persistence.queries.ObjectLevelReadQuery;
import org.eclipse.persistence.queries.ReadAllQuery;
import org.eclipse.persistence.queries.ReadObjectQuery;
import org.eclipse.persistence.queries.ReportQuery;
import org.eclipse.persistence.queries.SQLCall;
import org.eclipse.persistence.queries.UpdateAllQuery;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.IdentityHashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Vector;
/**
* Purpose:
* Mechanism used for all expression read queries.
* ExpressionQueryInterface understands how to deal with expressions.
*
Responsibilities:
* Translates the expression and creates the appropriate SQL statements.
* Retrieves the data from the database and return the results to the query.
*
* @author Yvon Lavoie
* @since TOPLink/Java 1.0
*/
public class ExpressionQueryMechanism extends StatementQueryMechanism {
protected Expression selectionCriteria;
public ExpressionQueryMechanism() {
}
/**
* Initialize the state of the query
* @param query - owner of mechanism
*/
public ExpressionQueryMechanism(DatabaseQuery query) {
super(query);
}
/**
* Initialize the state of the query
* @param query - owner of mechanism
* @param expression - selection criteria
*/
public ExpressionQueryMechanism(DatabaseQuery query, Expression expression) {
super(query);
this.selectionCriteria = expression;
}
/**
* Alias the supplied fields with respect to the expression node. Return copies of the fields
*/
protected Vector aliasFields(ObjectExpression node, List fields) {
Vector result = new Vector(fields.size());
for (Iterator iterator = fields.iterator(); iterator.hasNext();) {
DatabaseField eachField = ((DatabaseField) iterator.next()).clone();
eachField.setTable(node.aliasForTable(eachField.getTable()));
result.add(eachField);
}
return result;
}
/**
* If the fields in the statement have been pre-set, e.g. for a subset of the fields
* in a partial attribute read, report query, or just a query for the class indicator,
* then try to alias those. Right now this just guesses that they're all from the base.
*/
public List aliasPresetFields(SQLSelectStatement statement) {
List fields = statement.getFields();
Expression exp = statement.getWhereClause();
if (exp == null) {
return fields;
} else {
ExpressionBuilder base = exp.getBuilder();
return aliasFields(base, fields);
}
}
/**
* Create the appropriate where clause.
* Since this is where the selection criteria gets cloned for the first time
* (long after the owning query has been) many interesting things happen here.
*/
public Expression buildBaseSelectionCriteria(boolean isSubSelect, Map clonedExpressions) {
return buildBaseSelectionCriteria(isSubSelect, clonedExpressions, true);
}
/**
* Create the appropriate where clause.
* Since this is where the selection criteria gets cloned for the first time
* (long after the owning query has been) many interesting things happen here.
* Ability to switch off AdditionalJoinExpression is required for DeleteAllQuery.
*/
public Expression buildBaseSelectionCriteria(boolean isSubSelect, Map clonedExpressions, boolean shouldUseAdditionalJoinExpression) {
Expression expression = getSelectionCriteria();
// For Flashback: builder.asOf(value) counts as a non-trivial selection criteria.
// Also for bug 2612185 try to preserve the original builder as far as possible.
if ((expression == null) && getQuery().isObjectLevelReadQuery()) {
expression = ((ObjectLevelReadQuery)getQuery()).getExpressionBuilder();
}
// Subselects are not cloned, as they are cloned in the context of the parent expression.
if ((!isSubSelect) && (expression != null)) {
// For bug 2612185 specify the identity hashtable to be used in cloning so
// it is not thrown away at the end of cloning.
expression = expression.copiedVersionFrom(clonedExpressions);
}
if (expression != null && getQuery().isObjectLevelReadQuery()){
//reset any new ExpressionBuilders in the expression that do not belong to the query and are not
//parallel
ExpressionBuilder builder = ((ObjectLevelReadQuery)getQuery()).getExpressionBuilder();
if ((!isSubSelect) && (builder != null)) {
builder = (ExpressionBuilder)builder.copiedVersionFrom(clonedExpressions);
}
expression.resetPlaceHolderBuilder(builder);
}
// Leaf inheritance and multiple table join.
if (getDescriptor().shouldUseAdditionalJoinExpression()) {
DescriptorQueryManager queryManager = getDescriptor().getQueryManager();
Expression additionalJoin;
if (shouldUseAdditionalJoinExpression) {
additionalJoin = queryManager.getAdditionalJoinExpression();
} else {
additionalJoin = queryManager.getMultipleTableJoinExpression();
if (additionalJoin == null) {
return expression;
}
}
// If there's an expression, then we know we'll have to rebuild anyway, so don't clone.
if (expression == null) {
// Should never happen...
expression = additionalJoin.clone();
} else {
if (query.isObjectLevelReadQuery()){
ExpressionBuilder builder = ((ObjectLevelReadQuery)query).getExpressionBuilder();
if ((additionalJoin.getBuilder() != builder) && (additionalJoin.getBuilder().getQueryClass() == null)) {
if ((!isSubSelect) && (builder != null)) {
builder = (ExpressionBuilder)builder.copiedVersionFrom(clonedExpressions);
}
additionalJoin = additionalJoin.rebuildOn(builder);
}
}
expression = expression.and(additionalJoin);
}
// set wasAdditionalJoinCriteriaUsed on the addionalJoin because the expression may not have the correct builder as its left most builder
additionalJoin.getBuilder().setWasAdditionJoinCriteriaUsed(true);
}
return expression;
}
/**
* Return the appropriate select statement containing the fields in the table.
*/
public SQLSelectStatement buildBaseSelectStatement(boolean isSubSelect, Map clonedExpressions) {
return buildBaseSelectStatement(isSubSelect, clonedExpressions, true);
}
/**
* Return the appropriate select statement containing the fields in the table.
* Ability to switch off AdditionalJoinExpression is required for DeleteAllQuery.
*/
public SQLSelectStatement buildBaseSelectStatement(boolean isSubSelect, Map clonedExpressions, boolean shouldUseAdditionalJoinExpression) {
SQLSelectStatement selectStatement = new SQLSelectStatement();
ObjectLevelReadQuery query = (ObjectLevelReadQuery)getQuery();
selectStatement.setQuery(query);
selectStatement.setLockingClause(query.getLockingClause());
selectStatement.setDistinctState(query.getDistinctState());
selectStatement.setTables((List) ((ArrayList) getDescriptor().getTables()).clone());
selectStatement.setWhereClause(buildBaseSelectionCriteria(isSubSelect, clonedExpressions, shouldUseAdditionalJoinExpression));
//make sure we use the cloned builder and make sure we get the builder from the query if we have set the type.
// If we use the expression builder and there are parallel builders and the query builder is on the 'right'
//instead of the 'left' we will build the SQL using the wrong builder.
if (query.hasDefaultBuilder() && !query.getExpressionBuilder().wasQueryClassSetInternally()){
selectStatement.setBuilder((ExpressionBuilder)query.getExpressionBuilder().copiedVersionFrom(clonedExpressions));
}
//For bug 5900782, the clone of the OrderBy expressions needs to be used to ensure they are normalized
//every time when select SQL statement gets re-prepared, which will further guarantee the calculation
//of table alias always be correct
if (query.hasOrderByExpressions()) {
selectStatement.setOrderByExpressions(cloneExpressions(query.getOrderByExpressions(), clonedExpressions));
}
if (query.hasNonFetchJoinedAttributeExpressions()) {
selectStatement.setNonSelectFields(cloneExpressions(query.getNonFetchJoinAttributeExpressions(), clonedExpressions));
}
if (query.hasUnionExpressions()) {
selectStatement.setUnionExpressions(cloneExpressions(query.getUnionExpressions(), clonedExpressions));
}
if (getQuery().isReadAllQuery() && ((ReadAllQuery)getQuery()).hasHierarchicalExpressions()) {
ReadAllQuery readAllquery = (ReadAllQuery)query;
Expression startsWith = readAllquery.getStartWithExpression();
if (startsWith != null) {
startsWith.copiedVersionFrom(clonedExpressions);
}
selectStatement.setHierarchicalQueryExpressions(
startsWith,
readAllquery.getConnectByExpression().copiedVersionFrom(clonedExpressions),
cloneExpressions(readAllquery.getOrderSiblingsByExpressions(), clonedExpressions),
readAllquery.getDirection());
}
selectStatement.setHintString(query.getHintString());
selectStatement.setTranslationRow(getTranslationRow());
return selectStatement;
}
/**
* Return the appropriate select statement containing the fields in the table.
* This is used as a second read to a concrete class with subclasses in an abstract-multiple table read.
*/
protected SQLSelectStatement buildConcreteSelectStatement() {
// 2612538 - the default size of Map (32) is appropriate
Map clonedExpressions = new IdentityHashMap<>();
SQLSelectStatement selectStatement = buildBaseSelectStatement(false, clonedExpressions);
ClassDescriptor descriptor = getDescriptor();
InheritancePolicy policy = descriptor.getInheritancePolicy();
// The onlyInstances expression is only included on leaf descriptor base select,
// so if a root or branch (!shouldReadSubclasses means leaf), then it must be appended.
if (policy.shouldReadSubclasses()) {
Expression indicatorExpression = null;
// If the descriptor is a single table branch, then select the whole branch in a single query.
if (this.query.isReadAllQuery() && policy.hasChildren() && !policy.hasMultipleTableChild()) {
indicatorExpression = policy.getWithAllSubclassesExpression();
} else {
indicatorExpression = policy.getOnlyInstancesExpression();
}
if ((indicatorExpression != null) && (selectStatement.getWhereClause() != null)) {
selectStatement.setWhereClause(selectStatement.getWhereClause().and(indicatorExpression));
} else if (indicatorExpression != null) {
selectStatement.setWhereClause(indicatorExpression.clone());
}
}
selectStatement.setFields(getSelectionFields(selectStatement, false));
selectStatement.normalize(getSession(), descriptor, clonedExpressions);
// Allow for joining indexes to be computed to ensure distinct rows.
if (((ObjectLevelReadQuery)this.query).hasJoining()) {
((ObjectLevelReadQuery)this.query).getJoinedAttributeManager().computeJoiningMappingIndexes(false, getSession(), 0);
}
return selectStatement;
}
/**
* Return the appropriate delete statement
* Passing of a call/ statement pair is used because the same pair
* may be used several times.
* More elegant orangement of passing just a statement and creating the call
* in the method was rejected because the same call would've been potentially
* re-created several times.
* Preconditions:
* if selectCallForExist != null then selectStatementForExist != null;
* if selectCallForNotExist != null then selectStatementForNotExist != null.
* @return SQLDeleteStatement
*/
protected SQLDeleteStatement buildDeleteAllStatement(DatabaseTable table, Expression inheritanceExpression,
SQLCall selectCallForExist, SQLSelectStatement selectStatementForExist,
SQLCall selectCallForNotExist, SQLSelectStatement selectStatementForNotExist,
Collection primaryKeyFields) {
if(selectCallForExist == null && selectCallForNotExist == null) {
return buildDeleteStatementForDeleteAllQuery(table, inheritanceExpression);
}
SQLDeleteAllStatement deleteAllStatement = new SQLDeleteAllStatement();
deleteAllStatement.setTable(table);
deleteAllStatement.setTranslationRow(getTranslationRow());
if(selectCallForExist != null) {
deleteAllStatement.setSelectCallForExist(selectCallForExist);
// if selectStatementForExist doesn't require aliasing and targets the same
// table as the statement to be built,
// then instead of creating sql with "WHERE EXISTS("
// sql is created by extracting where clause from selectStatementForExist,
// for instance:
// DELETE FROM PROJECT WHERE (PROJ_NAME = ?)
// instead of the wrong one:
// DELETE FROM PROJECT WHERE EXISTS(SELECT PROJ_ID FROM PROJECT WHERE (PROJ_NAME = ?) AND PROJECT.PROJ_ID = PROJECT.PROJ_ID)
deleteAllStatement.setShouldExtractWhereClauseFromSelectCallForExist(!selectStatementForExist.requiresAliases() && table.equals(selectStatementForExist.getTables().get(0)));
deleteAllStatement.setTableAliasInSelectCallForExist(getAliasTableName(selectStatementForExist, table, getExecutionSession().getPlatform()));
} else {
// inheritanceExpression is irrelevant in case selectCallForExist != null
if(inheritanceExpression != null) {
deleteAllStatement.setInheritanceExpression(inheritanceExpression.clone());
}
}
if(selectCallForNotExist != null) {
deleteAllStatement.setSelectCallForNotExist(selectCallForNotExist);
deleteAllStatement.setTableAliasInSelectCallForNotExist(getAliasTableName(selectStatementForNotExist, table, getExecutionSession().getPlatform()));
}
deleteAllStatement.setPrimaryKeyFieldsForAutoJoin(primaryKeyFields);
return deleteAllStatement;
}
/**
* Create SQLDeleteAllStatements for mappings that may be responsible for references
* to the objects to be deleted
* in the tables NOT mapped to any class: ManyToManyMapping and DirectCollectionMapping
*
* NOTE: A similar pattern also used in method buildDeleteAllStatementsForMappingsWithTempTable():
* if you are updating this method consider applying a similar update to that method as well.
*
* @return {@code Vector}
*/
protected SQLDeleteStatement buildDeleteAllStatementForMapping(SQLCall selectCallForExist, SQLSelectStatement selectStatementForExist, List sourceFields, List targetFields) {
DatabaseTable targetTable = targetFields.get(0).getTable();
if(selectCallForExist == null) {
return buildDeleteStatementForDeleteAllQuery(targetTable);
}
SQLDeleteAllStatement deleteAllStatement = new SQLDeleteAllStatement();
deleteAllStatement.setTable(targetTable);
deleteAllStatement.setTranslationRow(getTranslationRow());
deleteAllStatement.setSelectCallForExist(selectCallForExist);
DatabaseTable sourceTable = sourceFields.get(0).getTable();
if(selectStatementForExist != null) {
deleteAllStatement.setTableAliasInSelectCallForExist(getAliasTableName(selectStatementForExist, sourceTable, getExecutionSession().getPlatform()));
}
deleteAllStatement.setAliasedFieldsForJoin(sourceFields);
deleteAllStatement.setOriginalFieldsForJoin(targetFields);
return deleteAllStatement;
}
/**
* Build delete statements with temporary table for ManyToMany and DirectCollection mappings.
*
* NOTE: A similar pattern also used in method buildDeleteAllStatementsForMappings():
* if you are updating this method consider applying a similar update to that method as well.
*
* @return {@code List}
*/
protected List buildDeleteAllStatementsForMappingsWithTempTable(ClassDescriptor descriptor, DatabaseTable rootTable, boolean dontCheckDescriptor) {
List deleteStatements = new ArrayList<>();
for (DatabaseMapping mapping : descriptor.getMappings()) {
if (mapping.isForeignReferenceMapping()) {
List sourceFields = null;
List targetFields = null;
if (mapping.isDirectCollectionMapping()) {
if (shouldBuildDeleteStatementForMapping((DirectCollectionMapping)mapping, dontCheckDescriptor, descriptor)) {
sourceFields = ((DirectCollectionMapping)mapping).getSourceKeyFields();
targetFields = ((DirectCollectionMapping)mapping).getReferenceKeyFields();
}
} else if (mapping.isAggregateCollectionMapping()) {
if (shouldBuildDeleteStatementForMapping((AggregateCollectionMapping)mapping, dontCheckDescriptor, descriptor)) {
sourceFields = ((AggregateCollectionMapping)mapping).getSourceKeyFields();
targetFields = ((AggregateCollectionMapping)mapping).getTargetForeignKeyFields();
}
} else if (mapping.isManyToManyMapping()) {
if (shouldBuildDeleteStatementForMapping((ManyToManyMapping)mapping, dontCheckDescriptor, descriptor)) {
RelationTableMechanism relationTableMechanism = ((ManyToManyMapping)mapping).getRelationTableMechanism();
sourceFields = relationTableMechanism.getSourceKeyFields();
targetFields = relationTableMechanism.getSourceRelationKeyFields();
}
} else if (mapping.isOneToOneMapping()) {
RelationTableMechanism relationTableMechanism = ((OneToOneMapping)mapping).getRelationTableMechanism();
if (relationTableMechanism != null) {
if (shouldBuildDeleteStatementForMapping((OneToOneMapping)mapping, dontCheckDescriptor, descriptor)) {
sourceFields = relationTableMechanism.getSourceKeyFields();
targetFields = relationTableMechanism.getSourceRelationKeyFields();
}
}
}
if (sourceFields != null) {
DatabaseTable targetTable = targetFields.get(0).getTable();
SQLDeleteAllStatementForTempTable deleteStatement
= buildDeleteAllStatementForTempTable(rootTable, sourceFields, targetTable, targetFields);
deleteStatements.add(deleteStatement);
}
}
}
return deleteStatements;
}
protected boolean shouldBuildDeleteStatementForMapping(ForeignReferenceMapping frMapping, boolean dontCheckDescriptor, ClassDescriptor descriptor) {
return (dontCheckDescriptor || frMapping.getDescriptor().equals(descriptor))
&& !(frMapping.isCascadeOnDeleteSetOnDatabase());
}
protected static String getAliasTableName(SQLSelectStatement selectStatement, DatabaseTable table, DatasourcePlatform platform) {
if(!selectStatement.requiresAliases()) {
return null;
}
Set aliasTables = new HashSet<>();
Iterator> itEntries = selectStatement.getTableAliases().entrySet().iterator();
DatabaseTable aliasTable = null;
while(itEntries.hasNext()) {
Map.Entry entry = itEntries.next();
if(table.equals(entry.getValue())) {
aliasTable = entry.getKey();
aliasTables.add(aliasTable);
}
}
if(aliasTables.isEmpty()) {
return null;
} else if(aliasTables.size() == 1) {
return aliasTable.getQualifiedNameDelimited(platform);
}
// The table has several aliases,
// remove the aliases that used by DataExpressions
// with baseExpression NOT the expressionBuilder used by the statement
ExpressionIterator> expIterator = new ExpressionIterator<>() {
@Override
public void iterate(Expression each) {
if(each instanceof DataExpression dataExpression) {
DatabaseField field = dataExpression.getField();
if(field != null) {
if(dataExpression.getBaseExpression() != getStatement().getBuilder()) {
getResult().remove(dataExpression.getAliasedField().getTable());
}
}
}
}
@Override
public boolean shouldIterateOverSubSelects() {
return true;
}
};
expIterator.setStatement(selectStatement);
expIterator.setResult(aliasTables);
expIterator.iterateOn(selectStatement.getWhereClause());
if(aliasTables.size() == 1) {
aliasTable = aliasTables.iterator().next();
return aliasTable.getQualifiedName();
} else if(aliasTables.isEmpty()) {
// should never happen
return aliasTable.getQualifiedName();
} else {
// should never happen
aliasTable = aliasTables.iterator().next();
return aliasTable.getQualifiedName();
}
}
/**
* Used by DeleteAllQuery to create DeleteStatement in a simple case
* when selectionCriteria==null.
*/
protected SQLDeleteStatement buildDeleteStatementForDeleteAllQuery(DatabaseTable table) {
return buildDeleteStatementForDeleteAllQuery(table, null);
}
/**
* Used by DeleteAllQuery to create DeleteStatement in a simple case
* when selectionCriteria==null.
*/
protected SQLDeleteStatement buildDeleteStatementForDeleteAllQuery(DatabaseTable table, Expression inheritanceExpression) {
SQLDeleteStatement deleteStatement = new SQLDeleteStatement();
if(inheritanceExpression != null) {
deleteStatement.setWhereClause(inheritanceExpression.clone());
}
deleteStatement.setTable(table);
deleteStatement.setTranslationRow(getTranslationRow());
deleteStatement.setHintString(getQuery().getHintString());
return deleteStatement;
}
/**
* Return the appropriate delete statement
*/
protected SQLDeleteStatement buildDeleteStatement(DatabaseTable table) {
SQLDeleteStatement deleteStatement = new SQLDeleteStatement();
Expression whereClause;
whereClause = getDescriptor().getObjectBuilder().buildDeleteExpression(table, getTranslationRow(), ((DeleteObjectQuery)getQuery()).usesOptimisticLocking());
deleteStatement.setWhereClause(whereClause);
deleteStatement.setTable(table);
deleteStatement.setTranslationRow(getTranslationRow());
deleteStatement.setHintString(getQuery().getHintString());
return deleteStatement;
}
/**
* Return the appropriate insert statement
*/
protected SQLInsertStatement buildInsertStatement(DatabaseTable table) {
SQLInsertStatement insertStatement = new SQLInsertStatement();
insertStatement.setTable(table);
insertStatement.setModifyRow(getModifyRow());
if (getDescriptor().hasReturningPolicies() && getDescriptor().getReturnFieldsToGenerateInsert() != null) {
// In case of RelationalDescriptor only return fields for current table must be used.
List returnFieldsForTable = new ArrayList<>();
for (DatabaseField item: getDescriptor().getReturnFieldsToGenerateInsert()) {
if (table.equals(item.getTable())) {
returnFieldsForTable.add(item);
}
}
if (!returnFieldsForTable.isEmpty()) {
insertStatement.setReturnFields(getDescriptor().getReturnFieldsToGenerateInsert());
}
}
insertStatement.setHintString(getQuery().getHintString());
return insertStatement;
}
/**
* Return the appropriate select statement containing the fields in the table.
*/
protected SQLSelectStatement buildNormalSelectStatement() {
// From bug 2612185 Remember the identity hashtable used in cloning the selection criteria even in the normal case
// for performance, in case subqueries need it, or for order by expressions.
// 2612538 - the default size of Map (32) is appropriate
Map clonedExpressions = new IdentityHashMap<>();
SQLSelectStatement selectStatement = buildBaseSelectStatement(false, clonedExpressions);
ObjectLevelReadQuery query = ((ObjectLevelReadQuery)getQuery());
// Case, normal read for branch inheritance class that reads subclasses all in its own table(s).
boolean includeAllSubclassesFields = true;
if (getDescriptor().hasInheritance()) {
getDescriptor().getInheritancePolicy().appendWithAllSubclassesExpression(selectStatement);
if ((!query.isReportQuery()) && query.shouldOuterJoinSubclasses()) {
selectStatement.getExpressionBuilder().setShouldUseOuterJoinForMultitableInheritance(true);
}
// Bug 380929 - Find whether to include all subclass fields or not.
includeAllSubclassesFields = shouldIncludeAllSubclassFields(selectStatement);
}
selectStatement.setFields(getSelectionFields(selectStatement, includeAllSubclassesFields));
selectStatement.normalize(getSession(), getDescriptor(), clonedExpressions);
// Allow for joining indexes to be computed to ensure distinct rows.
if (((ObjectLevelReadQuery)getQuery()).hasJoining()) {
((ObjectLevelReadQuery)getQuery()).getJoinedAttributeManager().computeJoiningMappingIndexes(true, getSession(), 0);
}
return selectStatement;
}
/**
* Return whether to include all subclass fields in select statement or not.
*/
protected boolean shouldIncludeAllSubclassFields(SQLSelectStatement selectStatement) {
ExpressionBuilder builder = selectStatement.getBuilder();
if (builder == null) {
if (selectStatement.getWhereClause() == null) {
return true;
} else {
builder = selectStatement.getWhereClause().getBuilder();
}
}
if (!builder.doesNotRepresentAnObjectInTheQuery()) {
if (getDescriptor() != null && getDescriptor().hasInheritance()) {
return !builder.isDowncast(getDescriptor(), getSession());
}
}
return true;
}
/**
* Return the appropriate select statement containing the fields in the table.
* Similar to super except the buildBaseSelectStatement will look after setting
* the fields to select.
*/
protected SQLSelectStatement buildReportQuerySelectStatement(boolean isSubSelect) {
return buildReportQuerySelectStatement(isSubSelect, false, null, true);
}
/**
* Customary inheritance expression is required for DeleteAllQuery and UpdateAllQuery preparation.
* Ability to switch off AdditionalJoinExpression is required for DeleteAllQuery.
*/
protected SQLSelectStatement buildReportQuerySelectStatement(boolean isSubSelect, boolean useCustomaryInheritanceExpression, Expression inheritanceExpression, boolean shouldUseAdditionalJoinExpression) {
ReportQuery reportQuery = (ReportQuery)getQuery();
// For bug 2612185: Need to know which original bases were mapped to which cloned bases.
// For sub-seclets the expressions have already been clones, and identity must be maintained with the outer expression.
Map clonedExpressions = isSubSelect ? null : new IdentityHashMap<>();
SQLSelectStatement selectStatement = buildBaseSelectStatement(isSubSelect, clonedExpressions, shouldUseAdditionalJoinExpression);
if (reportQuery.hasGroupByExpressions()) {
selectStatement.setGroupByExpressions(cloneExpressions(reportQuery.getGroupByExpressions(), clonedExpressions));
}
if (reportQuery.getHavingExpression() != null) {
selectStatement.setHavingExpression(reportQuery.getHavingExpression().copiedVersionFrom(clonedExpressions));
}
if (getDescriptor().hasInheritance()) {
if (useCustomaryInheritanceExpression) {
if (inheritanceExpression != null) {
if (selectStatement.getWhereClause() == null) {
selectStatement.setWhereClause(inheritanceExpression.clone());
} else {
selectStatement.setWhereClause(selectStatement.getWhereClause().and(inheritanceExpression));
}
}
} else {
getDescriptor().getInheritancePolicy().appendWithAllSubclassesExpression(selectStatement);
if (reportQuery.shouldOuterJoinSubclasses()) {
selectStatement.getExpressionBuilder().setShouldUseOuterJoinForMultitableInheritance(true);
}
}
}
Vector fieldExpressions = reportQuery.getQueryExpressions();
int itemOffset = fieldExpressions.size();
List items = reportQuery.getItems();
computeFieldExpressions(items, clonedExpressions, selectStatement, fieldExpressions);
selectStatement.setFields(fieldExpressions);
if (reportQuery.hasNonFetchJoinedAttributeExpressions()) {
selectStatement.setNonSelectFields(cloneExpressions(reportQuery.getNonFetchJoinAttributeExpressions(), clonedExpressions));
}
// Subselects must be normalized in the context of the parent statement.
if (!isSubSelect) {
selectStatement.normalize(getSession(), getDescriptor(), clonedExpressions);
}
items = reportQuery.getItems();
computeAndSetItemOffset(reportQuery, items, itemOffset);
return selectStatement;
}
private void computeFieldExpressions(List items, Map clonedExpressions, SQLSelectStatement selectStatement, Vector fieldExpressions) {
for (ReportItem item : items) {
if (item.isConstructorItem()) {
List reportItems = ((ConstructorReportItem) item).getReportItems();
computeFieldExpressions(reportItems, clonedExpressions, selectStatement, fieldExpressions);
} else {
extractStatementFromItem(item, clonedExpressions, selectStatement, fieldExpressions);
}
}
}
private void extractStatementFromItem(ReportItem item, Map clonedExpressions, SQLSelectStatement selectStatement, Vector fieldExpressions){
if (item.getAttributeExpression() != null) {
// this allows us to modify the item expression without modifying the original in case of re-prepare
Expression attributeExpression = item.getAttributeExpression();
ExpressionBuilder clonedBuilder = attributeExpression.getBuilder();
if (clonedBuilder.wasQueryClassSetInternally() && ((ReportQuery)getQuery()).getExpressionBuilder() != clonedBuilder) {
// no class specified so use statement builder as it is non-parallel
// must have same builder as it will be initialized
clonedBuilder = selectStatement.getBuilder();
attributeExpression = attributeExpression.rebuildOn(clonedBuilder);
} else if (clonedExpressions != null && clonedExpressions.get(clonedBuilder) != null) {
Expression cloneExpression = (Expression)clonedExpressions.get(attributeExpression);
if ((cloneExpression != null) && !cloneExpression.isExpressionBuilder()) {
attributeExpression = cloneExpression;
} else {
//The builder has been cloned ensure that the cloned builder is used
//in the items.
clonedBuilder = (ExpressionBuilder)clonedBuilder.copiedVersionFrom(clonedExpressions);
attributeExpression = attributeExpression.copiedVersionFrom(clonedExpressions);
}
}
if (attributeExpression.isExpressionBuilder()
&& (item.getDescriptor().getQueryManager().getAdditionalJoinExpression() != null)
&& !(clonedBuilder.wasAdditionJoinCriteriaUsed())) {
//Clone the standard join expression set on the descriptor's QueryManager
Expression additionalJoinExpression = item.getDescriptor().getQueryManager().getAdditionalJoinExpression().rebuildOn(clonedBuilder);
Expression whereClause = selectStatement.getWhereClause();
//'shouldUseOuterJoin' should have been set during query parsing; see ObjectExpression.leftJoin()
//So we need to alter the additionalJoinExpression to account for NULL on the right side
if(((ExpressionBuilder)attributeExpression).shouldUseOuterJoin()) {
additionalJoinExpression = additionalJoinExpression.or(attributeExpression.isNull());
}
if (whereClause == null ) {
selectStatement.setWhereClause(additionalJoinExpression);
} else {
selectStatement.setWhereClause(whereClause.and(additionalJoinExpression));
}
clonedBuilder.setWasAdditionJoinCriteriaUsed(true);
}
fieldExpressions.add(attributeExpression);
if (item.hasJoining()){
fieldExpressions.addAll(item.getJoinedAttributeManager().getJoinedAttributeExpressions());
fieldExpressions.addAll(item.getJoinedAttributeManager().getJoinedMappingExpressions());
}
}
}
/**
* Return the appropriate select statement to perform a does exist check
* @param field fields for does exist check.
*/
protected SQLSelectStatement buildSelectStatementForDoesExist(DatabaseField field) {
// Build appropriate select statement
SQLSelectStatement selectStatement;
selectStatement = new SQLSelectStatement();
selectStatement.addField(field);
selectStatement.setWhereClause(getDescriptor().getObjectBuilder().getPrimaryKeyExpression().clone().and(getDescriptor().getQueryManager().getAdditionalJoinExpression()));
selectStatement.setTranslationRow(getTranslationRow());
selectStatement.normalize(getSession(), getQuery().getDescriptor());
selectStatement.setHintString(getQuery().getHintString());
return selectStatement;
}
protected SQLUpdateAllStatement buildUpdateAllStatement(DatabaseTable table,
Map databaseFieldsToValues,
SQLCall selectCallForExist, SQLSelectStatement selectStatementForExist,
Collection primaryKeyFields)
{
SQLUpdateAllStatement updateAllStatement = new SQLUpdateAllStatement();
updateAllStatement.setTable(table);
updateAllStatement.setTranslationRow(getTranslationRow());
Map databaseFieldsToValuesCopy = new HashMap<>(databaseFieldsToValues.size());
Map databaseFieldsToTableAliases = null;
Iterator> it = databaseFieldsToValues.entrySet().iterator();
while(it.hasNext()) {
Map.Entry entry = it.next();
// for each table to be updated
DatabaseField field = entry.getKey();
// here's a Map of left hand fields to right hand expressions
Expression value = entry.getValue();
if(value.shouldCreateSQLSelectStatement()) {
SQLSelectStatement selStatement = createSQLSelectStatementForAssignedExpressionForUpdateAll(value);
SQLCall selCall = (SQLCall)selStatement.buildCall(getSession());
databaseFieldsToValuesCopy.put(field, selCall);
if(databaseFieldsToTableAliases == null) {
databaseFieldsToTableAliases = new HashMap<>();
updateAllStatement.setPrimaryKeyFieldsForAutoJoin(primaryKeyFields);
}
databaseFieldsToTableAliases.put(field, getAliasTableName(selStatement, table, getExecutionSession().getPlatform()));
} else {
// should be Expression
databaseFieldsToValuesCopy.put(field, value);
}
}
updateAllStatement.setUpdateClauses(databaseFieldsToValuesCopy);
updateAllStatement.setDatabaseFieldsToTableAliases(databaseFieldsToTableAliases);
updateAllStatement.setSelectCallForExist(selectCallForExist);
updateAllStatement.setShouldExtractWhereClauseFromSelectCallForExist(!selectStatementForExist.requiresAliases() && table.equals(selectStatementForExist.getTables().get(0)));
updateAllStatement.setTableAliasInSelectCallForExist(getAliasTableName(selectStatementForExist, table, getExecutionSession().getPlatform()));
updateAllStatement.setPrimaryKeyFieldsForAutoJoin(primaryKeyFields);
return updateAllStatement;
}
/**
* Return the appropriate update statement
* @return SQLInsertStatement
*/
protected SQLUpdateStatement buildUpdateStatement(DatabaseTable table) {
SQLUpdateStatement updateStatement = new SQLUpdateStatement();
updateStatement.setModifyRow(getModifyRow());
updateStatement.setTranslationRow(getTranslationRow());
if (getDescriptor().hasReturningPolicies() && getDescriptor().getReturnFieldsToGenerateUpdate() != null) {
// In case of RelationalDescriptor only return fields for current table must be used.
List returnFieldsForTable = new ArrayList<>();
for (DatabaseField item: getDescriptor().getReturnFieldsToGenerateUpdate()) {
if (table.equals(item.getTable())) {
returnFieldsForTable.add(item);
}
if (!returnFieldsForTable.isEmpty()) {
updateStatement.setReturnFields(getDescriptor().getReturnFieldsToGenerateUpdate());
}
}
}
updateStatement.setTable(table);
updateStatement.setWhereClause(getDescriptor().getObjectBuilder().buildUpdateExpression(table, getTranslationRow(), getModifyRow()));
updateStatement.setHintString(getQuery().getHintString());
return updateStatement;
}
/**
* Perform a cache lookup for the query
* This is only called from read object query.
* The query has already checked that the cache should be checked.
*/
@Override
public Object checkCacheForObject(AbstractRecord translationRow, AbstractSession session) {
// For bug 2782991 a list of nearly 20 problems with this method have
// been fixed.
ReadObjectQuery query = getReadObjectQuery();
ClassDescriptor descriptor = getDescriptor();
boolean conforming = false;
UnitOfWorkImpl uow = null;
if (session.isUnitOfWork()) {
conforming = query.shouldConformResultsInUnitOfWork() || descriptor.shouldAlwaysConformResultsInUnitOfWork();
uow = (UnitOfWorkImpl)session;
}
// Set the in memory query policy automatically for conforming queries, unless the
// user specifies the most cautious one.
int policyToUse = query.getInMemoryQueryIndirectionPolicyState();
if (conforming && (policyToUse != InMemoryQueryIndirectionPolicy.SHOULD_TRIGGER_INDIRECTION)) {
// Bug 320764 - return not conformed by default, to avoid incorrect results being returned
policyToUse = InMemoryQueryIndirectionPolicy.SHOULD_IGNORE_EXCEPTION_RETURN_NOT_CONFORMED;
}
Object cachedObject = null;
Expression selectionCriteria = getSelectionCriteria();
// Perform a series of cache checks, in the following order...
// 1: If selection key or selection object, lookup by primary key.
// 1.5: If row has sopObject, lookup by its primary key.
// 2: If selection criteria null, take the first instance in cache.
// 3: If exact primary key expression, lookup by primary key.
// 4: If inexact primary key expression, lookup by primary key and see if it conforms.
// 5: Perform a linear search on the cache, calling doesConform on each object.
// 6: (Conforming) Search through new objects.
// Each check is more optimal than the next.
// Finally: (Conforming) check that any positive result was not deleted in the UnitOfWork.
// 1: If selection key or selection object, do lookup by primary key.
Object selectionKey = query.getSelectionId();
Object selectionObject = query.getSelectionObject();
if ((selectionKey != null) || (selectionObject != null)) {
if (selectionKey == null) {
selectionKey = descriptor.getObjectBuilder().extractPrimaryKeyFromObject(selectionObject, session, true);
if (selectionKey == null) {
// Has a null primary key, so must not exist.
return InvalidObject.instance;
}
// Must be checked separately as the expression and row is not yet set.
query.setSelectionId(selectionKey);
}
if (query.requiresDeferredLocks()) {
cachedObject = session.getIdentityMapAccessorInstance().getFromLocalIdentityMapWithDeferredLock(selectionKey, query.getReferenceClass(), false, descriptor);
} else {
cachedObject = session.getIdentityMapAccessorInstance().getFromLocalIdentityMap(selectionKey, query.getReferenceClass(), false, descriptor);
}
} else {
// 1.5: If row has sopObject, lookup by its primary key.
//
if (translationRow != null && translationRow.hasSopObject()) {
if (query.requiresDeferredLocks()) {
cachedObject = session.getIdentityMapAccessorInstance().getFromLocalIdentityMapWithDeferredLock(descriptor.getObjectBuilder().extractPrimaryKeyFromObject(translationRow.getSopObject(), session), query.getReferenceClass(), false, descriptor);
} else {
cachedObject = session.getIdentityMapAccessorInstance().getFromLocalIdentityMap(descriptor.getObjectBuilder().extractPrimaryKeyFromObject(translationRow.getSopObject(), session), query.getReferenceClass(), false, descriptor);
}
} else {
// 2: If selection criteria null, take any instance in cache.
//
if (selectionCriteria == null) {
// In future would like to always return something from cache.
if (query.shouldConformResultsInUnitOfWork() || descriptor.shouldAlwaysConformResultsInUnitOfWork() || query.shouldCheckCacheOnly() || query.shouldCheckCacheThenDatabase()) {
cachedObject = session.getIdentityMapAccessorInstance().getFromIdentityMap(null, query.getReferenceClass(), translationRow, policyToUse, conforming, false, descriptor);
}
} else {
// 3: If can extract exact primary key expression, do lookup by primary key.
//
selectionKey = descriptor.getObjectBuilder().extractPrimaryKeyFromExpression(true, selectionCriteria, translationRow, session);
// If an exact primary key was extracted or should check cache by exact
// primary key only this will become the final check.
if ((selectionKey != null) || query.shouldCheckCacheByExactPrimaryKey()) {
if (selectionKey != null) {
// Check if key is invalid (null), cannot exist.
if (selectionKey == InvalidObject.instance) {
return selectionKey;
}
if (query.requiresDeferredLocks()) {
cachedObject = session.getIdentityMapAccessorInstance().getFromLocalIdentityMapWithDeferredLock(selectionKey, query.getReferenceClass(), false, descriptor);
} else {
cachedObject = session.getIdentityMapAccessorInstance().getFromLocalIdentityMap(selectionKey, query.getReferenceClass(), false, descriptor);
}
// Because it was exact primary key if the lookup failed then it is not there.
}
} else {
// 4: If can extract inexact primary key, find one object by primary key and
// check if it conforms. Failure of this object to conform however does not
// rule out a cache hit.
Object inexactSelectionKey = descriptor.getObjectBuilder().extractPrimaryKeyFromExpression(false, selectionCriteria, translationRow, session);// Check for any primary key in expression, may have other stuff.
if (inexactSelectionKey != null) {
// Check if key is invalid (null), cannot exist.
if (selectionKey == InvalidObject.instance) {
return selectionKey;
}
// PERF: Only use deferred lock when required.
if (query.requiresDeferredLocks()) {
cachedObject = session.getIdentityMapAccessorInstance().getFromLocalIdentityMapWithDeferredLock(inexactSelectionKey, query.getReferenceClass(), false, descriptor);
} else {
cachedObject = session.getIdentityMapAccessorInstance().getFromLocalIdentityMap(inexactSelectionKey, query.getReferenceClass(), false, descriptor);
}
} else {
CacheKey cacheKey = descriptor.getCachePolicy().checkCacheByIndex(selectionCriteria, translationRow, descriptor, session);
if (cacheKey != null) {
if (query.requiresDeferredLocks()) {
cacheKey.checkDeferredLock();
} else {
cacheKey.checkReadLock();
}
cachedObject = cacheKey.getObject();
}
}
if (cachedObject != null) {
// Must ensure that it matches the expression.
try {
// PERF: 3639015 - cloning the expression no longer required
// when using the root session.
ExpressionBuilder builder = selectionCriteria.getBuilder();
builder.setSession(session.getRootSession(null));
builder.setQueryClass(descriptor.getJavaClass());
if (!selectionCriteria.doesConform(cachedObject, session, translationRow, policyToUse)) {
cachedObject = null;
}
} catch (QueryException exception) {// Ignore if expression too complex.
if (query.shouldCheckCacheOnly()) {// Throw on only cache.
throw exception;
}
cachedObject = null;
}
}
// 5: Perform a linear search of the cache, calling expression.doesConform on each element.
// This is a last resort linear time search of the identity map.
// This can be avoided by setting check cache by (inexact/exact) primary key on the query.
// That flag becomes invalid in the conforming case (bug 2609611: SUPPORT CONFORM RESULT IN UOW IN CONJUNCTION WITH OTHER IN-MEMORY FEATURES)
// so if conforming must always do this linear search, but at least only on
// objects registered in the UnitOfWork.
//
boolean conformingButOutsideUnitOfWork = ((query.shouldConformResultsInUnitOfWork() || descriptor.shouldAlwaysConformResultsInUnitOfWork()) && !session.isUnitOfWork());
if ((cachedObject == null) && (conforming || (!query.shouldCheckCacheByPrimaryKey() && !conformingButOutsideUnitOfWork))) {
// PERF: 3639015 - cloning the expression no longer required
// when using the root session
if (selectionCriteria != null) {
ExpressionBuilder builder = selectionCriteria.getBuilder();
builder.setSession(session.getRootSession(null));
builder.setQueryClass(descriptor.getJavaClass());
}
try {
cachedObject = session.getIdentityMapAccessorInstance().getFromIdentityMap(selectionCriteria, query.getReferenceClass(), translationRow, policyToUse, conforming, false, descriptor);
} catch (QueryException exception) {// Ignore if expression too complex.
if (query.shouldCheckCacheOnly()) {// Throw on only cache.
throw exception;
}
}
}
}
}
}
}
// 6: If unit of work search through new objects.
//
if (conforming) {
if (cachedObject == null) {
if (selectionKey != null) {
cachedObject = uow.getObjectFromNewObjects(query.getReferenceClass(), selectionKey);
} else {
// PERF: 3639015 - cloning the expression no longer required
// when using the root session
if (selectionCriteria != null) {
ExpressionBuilder builder = selectionCriteria.getBuilder();
builder.setSession(session.getRootSession(null));
builder.setQueryClass(descriptor.getJavaClass());
}
try {
cachedObject = uow.getObjectFromNewObjects(selectionCriteria, query.getReferenceClass(), translationRow, policyToUse);
} catch (QueryException exception) {
// Ignore if expression too complex.
}
}
}
// Finally, check that a positive result is not deleted in the Unit Of Work.
//
if (cachedObject != null) {
if (uow.isObjectDeleted(cachedObject)) {
if (selectionKey != null) {
// In this case return a special value, to notify
// that the object was found but null must be returned.
return InvalidObject.instance;
} else {
cachedObject = null;
}
}
}
}
if (cachedObject != null) {
// Fetch group check, ensure object is fetched.
if (descriptor.hasFetchGroupManager()) {
if (descriptor.getFetchGroupManager().isPartialObject(cachedObject)) {
FetchGroup fetchGroup = query.getExecutionFetchGroup(descriptor);
EntityFetchGroup entityFetchGroup = null;
if (fetchGroup!= null){
entityFetchGroup = descriptor.getFetchGroupManager().getEntityFetchGroup(fetchGroup);
}
if (!descriptor.getFetchGroupManager().isObjectValidForFetchGroup(cachedObject, entityFetchGroup)) {
//the cached object is partially fetched, and it's fetch group is not a superset of the one in the query, so the cached object is not valid for the query.
cachedObject = null;
}
}
}
}
// If only checking the cache, and empty, return invalid, unless it is a unit of work,
// in which case the parent cache still needs to be checked.
if ((cachedObject == null) && query.shouldCheckCacheOnly()
&& ((uow == null) || (!uow.isNestedUnitOfWork() && descriptor.getCachePolicy().shouldIsolateObjectsInUnitOfWork()))) {
return InvalidObject.instance;
}
return cachedObject;
}
/**
* The statement is no longer require after prepare so can be released.
*/
@Override
public void clearStatement() {
// Only clear the statement if it is an expression query, otherwise the statement may still be needed.
setSQLStatement(null);
setSQLStatements(null);
}
/**
* Clone the mechanism for the specified query clone.
* Should not try to clone statements.
*/
@Override
public DatabaseQueryMechanism clone(DatabaseQuery queryClone) {
DatabaseQueryMechanism clone = (DatabaseQueryMechanism)clone();
clone.setQuery(queryClone);
return clone;
}
/**
* Return an expression builder which is valid for us
*/
public ExpressionBuilder getExpressionBuilder() {
if (getSelectionCriteria() != null) {
return getSelectionCriteria().getBuilder();
}
return null;
}
/**
* Return the selection criteria of the query.
*/
@Override
public Expression getSelectionCriteria() {
return selectionCriteria;
}
/**
* Return the fields required in the select clause.
* This must now be called after normalization, so it will get the aliased fields
*/
public Vector getSelectionFields(SQLSelectStatement statement, boolean includeAllSubclassFields) {
ObjectLevelReadQuery owner = (ObjectLevelReadQuery)getQuery();
if (owner.hasPartialAttributeExpressions()) {
return owner.getPartialAttributeSelectionFields(false);
}
Vector fields = NonSynchronizedVector.newInstance();
if (owner.getExecutionFetchGroup() != null) {
fields.addAll(owner.getFetchGroupSelectionFields());
} else {
if (includeAllSubclassFields) {
fields.addAll(getDescriptor().getAllSelectionFields(owner));
} else {
fields.add(statement.getExpressionBuilder());
}
}
// Add joined fields.
if (owner.hasJoining()) {
owner.addJoinSelectionFields(fields, false);
}
if (owner.hasAdditionalFields()) {
// Add additional fields, use for batch reading m-m.
fields.addAll(owner.getAdditionalFields());
}
return fields;
}
/**
* Return true if this is an expression query mechanism.
*/
@Override
public boolean isExpressionQueryMechanism() {
return true;
}
/**
* Return true if this is a statement query mechanism
*/
@Override
public boolean isStatementQueryMechanism() {
return false;
}
/**
* Override super to do nothing.
*/
@Override
public void prepare() throws QueryException {
// Do nothing.
}
/**
* Pre-build the SQL statement from the expression.
*/
@Override
public void prepareCursorSelectAllRows() {
if (getQuery().isReportQuery()) {
SQLSelectStatement statement = buildReportQuerySelectStatement(false);
setSQLStatement(statement);
// For bug 2718118 inheritance with cursors is supported provided there is a read all subclasses view.
} else if (getDescriptor().hasInheritance() && getDescriptor().getInheritancePolicy().requiresMultipleTableSubclassRead() && getDescriptor().getInheritancePolicy().hasView()) {
InheritancePolicy inheritancePolicy = getDescriptor().getInheritancePolicy();
SQLSelectStatement statement = inheritancePolicy.buildViewSelectStatement((ObjectLevelReadQuery)getQuery());
setSQLStatement(statement);
} else {
setSQLStatement(buildNormalSelectStatement());
}
super.prepareCursorSelectAllRows();
}
/**
* Pre-build the SQL statement from the expression.
*/
@Override
public void prepareDeleteAll() {
prepareDeleteAll(null, false);
}
/**
* Pre-build the SQL statement from the expression.
*
* NOTE: A similar pattern also used in method buildDeleteAllStatementsForTempTable():
* if you are updating this method consider applying a similar update to that method as well.
*/
protected void prepareDeleteAll(List tablesToIgnore, boolean isWhereClauseRequired) {
List tablesInInsertOrder;
ClassDescriptor descriptor = getDescriptor();
if (tablesToIgnore == null) {
// It's original (not a nested) method call.
tablesInInsertOrder = descriptor.getMultipleTableInsertOrder();
} else {
// It's a nested method call: tableInInsertOrder filled with descriptor's tables (in insert order),
// the tables found in tablesToIgnore are thrown away -
// they have already been taken care of by the caller.
// In Employee example, query with reference class Project gets here
// to handle LPROJECT table; tablesToIgnore contains PROJECT table.
tablesInInsertOrder = new ArrayList(descriptor.getMultipleTableInsertOrder().size());
for (DatabaseTable table : descriptor.getMultipleTableInsertOrder()) {
if (!tablesToIgnore.contains(table)) {
tablesInInsertOrder.add(table);
}
}
}
// cache the flag - used many times
boolean hasInheritance = descriptor.hasInheritance();
if (!tablesInInsertOrder.isEmpty()) {
Expression whereClause = getSelectionCriteria();
if (tablesToIgnore == null) {
// It's original (not a nested) method call.
// Ignore the passed dummy value of isWhereClauseRequired and calculate it here.
// This value will be passed to all other tables.
isWhereClauseRequired = whereClause != null;
if (!isWhereClauseRequired) {
Expression additionalExpression = descriptor.getQueryManager().getAdditionalJoinExpression();
if (additionalExpression != null) {
if (!additionalExpression.equals(descriptor.getQueryManager().getMultipleTableJoinExpression())) {
isWhereClauseRequired = true;
}
}
}
}
SQLCall selectCallForExist = null;
// Most databases support delete cascade constraints by specifying a ON DELETE CASCADE option when defining foreign key constraints.
// However some databases which don't support foreign key constraints cannot use delete cascade constraints.
// Therefore each delete operation should be executed in such a database platform instead of delegating delete cascade constraints.
boolean supportForeignKeyConstraints = getSession().getPlatform().supportsForeignKeyConstraints();
boolean supportCascadeOnDelete = supportForeignKeyConstraints && descriptor.isCascadeOnDeleteSetOnDatabaseOnSecondaryTables();
boolean isSelectCallForNotExistRequired = (tablesToIgnore == null)
&& (tablesInInsertOrder.size() > 1) && (!supportCascadeOnDelete);
SQLSelectStatement selectStatementForNotExist = null;
SQLCall selectCallForNotExist = null;
// inheritanceExpression is always null in a nested method call.
Expression inheritanceExpression = null;
if (tablesToIgnore == null) {
// It's original (not a nested) method call.
if (hasInheritance) {
if (descriptor.getInheritancePolicy().shouldReadSubclasses()) {
inheritanceExpression = descriptor.getInheritancePolicy().getWithAllSubclassesExpression();
} else {
inheritanceExpression = descriptor.getInheritancePolicy().getOnlyInstancesExpression();
}
}
}
SQLSelectStatement selectStatementForExist = createSQLSelectStatementForModifyAll(whereClause);
// Main Case: Descriptor is mapped to more than one table and/or the query references other tables
boolean isMainCase = selectStatementForExist.requiresAliases();
if (isMainCase) {
if (isWhereClauseRequired) {
if (getExecutionSession().getPlatform().shouldAlwaysUseTempStorageForModifyAll() && tablesToIgnore == null) {
// currently DeleteAll using Oracle anonymous block is not implemented
if(!getExecutionSession().getPlatform().isOracle()) {
prepareDeleteAllUsingTempStorage();
return;
}
}
if (isSelectCallForNotExistRequired) {
selectStatementForNotExist = createSQLSelectStatementForModifyAll(null, null, descriptor, true, false);
selectCallForNotExist = (SQLCall)selectStatementForNotExist.buildCall(getSession());
}
} else {
//whereClause = null
if (getExecutionSession().getPlatform().shouldAlwaysUseTempStorageForModifyAll() && tablesToIgnore == null) {
// currently DeleteAll using Oracle anonymous block is not implemented
if (!getExecutionSession().getPlatform().isOracle()) {
// the only case to handle without temp storage is inheritance root without inheritanceExpression:
// in this case all generated delete calls will have no where clauses.
if (hasInheritance && !(inheritanceExpression == null && descriptor.getInheritancePolicy().isRootParentDescriptor())) {
prepareDeleteAllUsingTempStorage();
return;
}
}
}
}
} else {
// simple case: Descriptor is mapped to a single table and the query references no other tables.
if (isWhereClauseRequired) {
if (getExecutionSession().getPlatform().shouldAlwaysUseTempStorageForModifyAll() && tablesToIgnore == null) {
// currently DeleteAll using Oracle anonymous block is not implemented
if (!getExecutionSession().getPlatform().isOracle()) {
// if there are derived classes with additional tables - use temporary storage
if (hasInheritance && descriptor.getInheritancePolicy().hasMultipleTableChild()) {
prepareDeleteAllUsingTempStorage();
return;
}
}
}
}
}
// Don't use selectCallForExist in case there is no whereClause -
// a simpler sql will be created if possible.
if (isWhereClauseRequired) {
selectCallForExist = (SQLCall)selectStatementForExist.buildCall(getSession());
}
if (isMainCase) {
// Main case: Descriptor is mapped to more than one table and/or the query references other tables
//
// Add and prepare to a call a delete statement for each table.
// In the case of multiple tables, build the sql statements list in insert order. When the
// actual SQL calls are sent they are sent in the reverse of this order.
for (DatabaseTable table : tablesInInsertOrder) {
Collection primaryKeyFields = getPrimaryKeyFieldsForTable(table);
SQLDeleteStatement deleteStatement;
// In Employee example, query with reference class:
// Employee will build "EXISTS" for SALARY and "NOT EXISTS" for EMPLOYEE;
// LargeProject will build "EXISTS" for LPROJECT and "NOT EXISTS" for Project.
// The situation is a bit more complex if more than two levels of inheritance is involved:
// both "EXISTS" and "NOT EXISTS" used for the "intermediate" (not first and not last) tables.
if (!isSelectCallForNotExistRequired) {
// isSelectCallForNotExistRequired == false:
// either tablesToIgnore != null: it's a nested method call.
// Example:
// In Employee example, query with reference class
// Project will get here to handle LPROJECT table
// or tablesInInsertOrder.size() == 1: there is only one table,
// but there is joining to at least one other table (otherwise would've been isMainCase==false).
//
// Note that buildDeleteAllStatement ignores inheritanceExpression if selectCallForExist!=null.
deleteStatement = buildDeleteAllStatement(table, inheritanceExpression, selectCallForExist, selectStatementForExist, null, null, primaryKeyFields);
} else {
// isSelectCallForNotExistRequired==true: original call, multiple tables.
// indicates whether the table is the last in insertion order
boolean isLastTable = table.equals(tablesInInsertOrder.get(tablesInInsertOrder.size() - 1));
if (inheritanceExpression == null) {
if(isLastTable) {
// In Employee example, query with reference class Employee calls this for SALARY table;
deleteStatement = buildDeleteAllStatement(table, null, selectCallForExist, selectStatementForExist, null, null, primaryKeyFields);
} else {
// In Employee example, query with reference class Employee calls this for EMPLOYEE table
deleteStatement = buildDeleteAllStatement(table, null, null, null, selectCallForNotExist, selectStatementForNotExist, primaryKeyFields);
}
} else {
// there is inheritance
if (table.equals(descriptor.getMultipleTableInsertOrder().get(0))) {
// This is the highest table in inheritance hierarchy - the one that contains conditions
// (usually class indicator fields) that defines the class identity.
// inheritanceExpression is for this table (it doesn't reference any other tables).
// In Employee example, query with reference class LargeProject calls this for PROJECT table
deleteStatement = buildDeleteAllStatement(table, inheritanceExpression, null, null, selectCallForNotExist, selectStatementForNotExist, primaryKeyFields);
} else {
ClassDescriptor desc = getHighestDescriptorMappingTable(table);
if (desc == descriptor) {
if (isLastTable) {
// In Employee example, query with reference class LargeProject calls this for LPROJECT table;
deleteStatement = buildDeleteAllStatement(table, null, selectCallForExist, selectStatementForExist, null, null, primaryKeyFields);
} else {
// Class has multiple tables that are not inherited.
// In extended Employee example:
// Employee2 class inherits from Employee and
// mapped to two additional tables: EMPLOYEE2 and SALARY2.
// Query with reference class Employee2 calls this for EMPLOYEE2 table.
deleteStatement = buildDeleteAllStatement(table, null, null, null, selectCallForNotExist, selectStatementForNotExist, primaryKeyFields);
}
} else {
// This table is mapped through descriptor that stands higher in inheritance hierarchy
// (but not the highest one - this is taken care in another case).
//
// inheritanceSelectStatementForExist is created for the higher descriptor,
// but the inheritance expression from the current descriptor is used.
// Note that this trick doesn't work in case the higher descriptor was defined with
// inheritance policy set not to read subclasses
// (descriptor.getInheritancePolicy().dontReadSubclassesOnQueries()).
// In that case inheritance expression for the higher descriptor can't
// be removed - it still appears in the sql and collides with the inheritance
// expression from the current descriptor - the selection expression is never true.
//
// In extended Employee example:
// VeryLargeProject inherits from LargeProject,
// mapped to an additional table VLPROJECT;
// VeryVeryLargeProject inherits from VeryLargeProject,
// mapped to the same tables as it's parent.
//
// Note that this doesn't work in case LargeProject descriptor was set not to read subclasses:
// in that case the selection expression will have (PROJ_TYPE = 'L') AND (PROJ_TYPE = 'V')
//
//bug 413765: this can only be called when selectCallForExist!=null. Other classes might use this table
// and be deleted if the inheritance info isn't included.
if(isLastTable && selectCallForExist!=null) {
// In extended Employee example:
// Query with reference class VeryVeryLargeProject calls this for VLPROJECT table.
deleteStatement = buildDeleteAllStatement(table, null, selectCallForExist, selectStatementForExist, null, null, primaryKeyFields);
} else {
// In extended Employee example:
// Query with reference class VeryLargeProject calls this for LPROJECT table.
// Note that both EXISTS and NOT EXISTS clauses created.
SQLSelectStatement inheritanceSelectStatementForExist = createSQLSelectStatementForModifyAll(null, inheritanceExpression, desc, true, true);
SQLCall inheritanceSelectCallForExist = (SQLCall)inheritanceSelectStatementForExist.buildCall(getSession());
deleteStatement = buildDeleteAllStatement(table, null, inheritanceSelectCallForExist, inheritanceSelectStatementForExist, selectCallForNotExist, selectStatementForNotExist, primaryKeyFields);
}
}
}
}
}
if (descriptor.getTables().size() > 1) {
getSQLStatements().add(deleteStatement);
} else {
setSQLStatement(deleteStatement);
}
// Only delete from first table if delete is cascaded on the database.
if (supportCascadeOnDelete) {
break;
}
}
} else {
// A simple case:
// there is only one table mapped to the descriptor, and
// selection criteria doesn't reference any other tables
// A simple sql call with no subselect should be built.
// In Employee example, query with reference class:
// Project will build a simple sql call for PROJECT(and will make nested method calls for LargeProject and SmallProject);
// SmallProject will build a simple sql call for PROJECT
setSQLStatement(buildDeleteAllStatement(descriptor.getDefaultTable(), inheritanceExpression, selectCallForExist, selectStatementForExist, null, null, null));
}
if (selectCallForExist == null) {
// Getting there means there is no whereClause.
// To handle the mappings selectCallForExist may be required in this case, too.
if (hasInheritance && (tablesToIgnore != null || inheritanceExpression != null)) {
// The only case NOT to create the call for no whereClause is either no inheritance,
// or it's an original (not a nested) method call and there is no inheritance expression.
// In Employee example:
// query with reference class Project and no where clause for m-to-m mapping generates:
// DELETE FROM EMP_PROJ;
// as opposed to query with reference class SmallProject:
// DELETE FROM EMP_PROJ WHERE EXISTS(SELECT PROJ_ID FROM PROJECT WHERE (PROJ_TYPE = ?) AND PROJ_ID = EMP_PROJ.PROJ_ID).
//
selectCallForExist = (SQLCall)selectStatementForExist.buildCall(getSession());
}
}
// Add statements for ManyToMany and DirectCollection mappings
List deleteStatementsForMappings = buildDeleteAllStatementsForMappings(selectCallForExist, selectStatementForExist, tablesToIgnore == null);
if(!deleteStatementsForMappings.isEmpty()) {
if(getSQLStatement() != null) {
getSQLStatements().add(getSQLStatement());
setSQLStatement(null);
}
getSQLStatements().addAll(deleteStatementsForMappings);
}
}
// Indicates whether the descriptor has children using extra tables.
boolean hasChildrenWithExtraTables = hasInheritance && descriptor.getInheritancePolicy().hasChildren() && descriptor.getInheritancePolicy().hasMultipleTableChild();
// TBD: should we ignore subclasses in case descriptor doesn't want us to read them in?
//** Currently in this code we do ignore.
//** If it will be decided that we need to handle children in all cases
//** the following statement should be changed to: boolean shouldHandleChildren = hasChildrenWithExtraTables;
boolean shouldHandleChildren = hasChildrenWithExtraTables && descriptor.getInheritancePolicy().shouldReadSubclasses();
// Perform a nested method call for each child
if (shouldHandleChildren) {
// In Employee example: query for Project will make nested calls to
// LargeProject and SmallProject and ask them to ignore PROJECT table
List tablesToIgnoreForChildren = new ArrayList<>();
// The tables this descriptor has ignored, its children also should ignore.
if (tablesToIgnore != null) {
tablesToIgnoreForChildren.addAll(tablesToIgnore);
}
// If the descriptor reads subclasses there is no need for
// subclasses to process its tables for the second time.
if (descriptor.getInheritancePolicy().shouldReadSubclasses()) {
tablesToIgnoreForChildren.addAll(tablesInInsertOrder);
}
Iterator it = descriptor.getInheritancePolicy().getChildDescriptors().iterator();
while (it.hasNext()) {
// Define the same query for the child
ClassDescriptor childDescriptor = it.next();
// Most databases support delete cascade constraints by specifying a ON DELETE CASCADE option when defining foreign key constraints.
// However some databases which don't support foreign key constraints cannot use delete cascade constraints.
// Therefore each delete operation should be executed in such a database platform instead of delegating delete cascade constraints.
boolean supportForeignKeyConstraints = getSession().getPlatform().supportsForeignKeyConstraints();
boolean supportCascadeOnDelete = supportForeignKeyConstraints && childDescriptor.isCascadeOnDeleteSetOnDatabaseOnSecondaryTables();
// Need to process only "multiple tables" child descriptors
if (((!supportCascadeOnDelete) && childDescriptor.getTables().size() > descriptor.getTables().size()) ||
(childDescriptor.getInheritancePolicy().hasMultipleTableChild()))
{
DeleteAllQuery childQuery = new DeleteAllQuery();
childQuery.setReferenceClass(childDescriptor.getJavaClass());
childQuery.setSelectionCriteria(getSelectionCriteria());
childQuery.setDescriptor(childDescriptor);
childQuery.setSession(getSession());
ExpressionQueryMechanism childMechanism = (ExpressionQueryMechanism)childQuery.getQueryMechanism();
// nested call
childMechanism.prepareDeleteAll(tablesToIgnoreForChildren, isWhereClauseRequired);
// Copy the statements from child query mechanism.
// In Employee example query for Project will pick up a statement for
// LPROJECT table from LargeProject and nothing from SmallProject.
List childStatements = new ArrayList<>();
if (childMechanism.getCall() != null) {
childStatements.add(childMechanism.getSQLStatement());
} else if(childMechanism.getSQLStatements() != null) {
childStatements.addAll(childMechanism.getSQLStatements());
}
if (!childStatements.isEmpty()) {
if (getSQLStatement() != null) {
getSQLStatements().add(getSQLStatement());
setSQLStatement(null);
}
getSQLStatements().addAll(childStatements);
}
}
}
}
// Nested method call doesn't need to call this.
if (tablesToIgnore == null) {
((DeleteAllQuery)getQuery()).setIsPreparedUsingTempStorage(false);
super.prepareDeleteAll();
}
}
protected void prepareDeleteAllUsingTempStorage() {
if(getExecutionSession().getPlatform().supportsTempTables()) {
prepareDeleteAllUsingTempTables();
} else {
throw QueryException.tempTablesNotSupported(getQuery(), getExecutionSession().getPlatform().getClass().getSimpleName());
}
}
protected void prepareDeleteAllUsingTempTables() {
getSQLStatements().addAll(buildStatementsForDeleteAllForTempTables());
((DeleteAllQuery)getQuery()).setIsPreparedUsingTempStorage(true);
super.prepareDeleteAll();
}
// Create SQLDeleteAllStatements for mappings that may be responsible for references
// to the objects to be deleted
// in the tables NOT mapped to any class: ManyToManyMapping and DirectCollectionMapping
/**
*
* NOTE: A similar pattern also used in method buildDeleteAllStatementsForMappingsWithTempTable:
* if you are updating this method consider applying a similar update to that method as well.
*
* @return {@code List}
*/
protected List buildDeleteAllStatementsForMappings(SQLCall selectCallForExist, SQLSelectStatement selectStatementForExist, boolean dontCheckDescriptor) {
List deleteStatements = new ArrayList<>();
ClassDescriptor descriptor = getDescriptor();
for (DatabaseMapping mapping : descriptor.getMappings()) {
if (mapping.isForeignReferenceMapping()) {
List sourceFields = null;
List targetFields = null;
if (mapping.isDirectCollectionMapping()) {
if (shouldBuildDeleteStatementForMapping((DirectCollectionMapping)mapping, dontCheckDescriptor, descriptor)) {
sourceFields = ((DirectCollectionMapping)mapping).getSourceKeyFields();
targetFields = ((DirectCollectionMapping)mapping).getReferenceKeyFields();
}
} else if (mapping.isAggregateCollectionMapping()) {
if (shouldBuildDeleteStatementForMapping((AggregateCollectionMapping)mapping, dontCheckDescriptor, descriptor)) {
sourceFields = ((AggregateCollectionMapping)mapping).getSourceKeyFields();
targetFields = ((AggregateCollectionMapping)mapping).getTargetForeignKeyFields();
}
} else if (mapping.isManyToManyMapping()) {
if (shouldBuildDeleteStatementForMapping((ManyToManyMapping)mapping, dontCheckDescriptor, descriptor)) {
RelationTableMechanism relationTableMechanism = ((ManyToManyMapping)mapping).getRelationTableMechanism();
sourceFields = relationTableMechanism.getSourceKeyFields();
targetFields = relationTableMechanism.getSourceRelationKeyFields();
}
} else if (mapping.isOneToOneMapping()) {
RelationTableMechanism relationTableMechanism = ((OneToOneMapping)mapping).getRelationTableMechanism();
if (relationTableMechanism != null) {
if (shouldBuildDeleteStatementForMapping((OneToOneMapping)mapping, dontCheckDescriptor, descriptor)) {
sourceFields = relationTableMechanism.getSourceKeyFields();
targetFields = relationTableMechanism.getSourceRelationKeyFields();
}
}
}
if (sourceFields != null) {
deleteStatements.add(buildDeleteAllStatementForMapping(selectCallForExist, selectStatementForExist, sourceFields, targetFields));
}
}
}
return deleteStatements;
}
protected SQLSelectStatement createSQLSelectStatementForModifyAll(Expression whereClause) {
return createSQLSelectStatementForModifyAll(whereClause, null, getDescriptor(), false, true);
}
/**
* Customary inheritance expression is required for DeleteAllQuery and UpdateAllQuery preparation.
* Ability to switch off AdditionalJoinExpression is required for DeleteAllQuery.
*/
protected SQLSelectStatement createSQLSelectStatementForModifyAll(Expression whereClause, Expression inheritanceExpression,
ClassDescriptor desc, boolean useCustomaryInheritanceExpression, boolean shouldUseAdditionalJoinExpression)
{
ExpressionBuilder builder;
if(whereClause != null) {
whereClause = whereClause.clone();
builder = whereClause.getBuilder();
} else {
builder = new ExpressionBuilder();
}
ReportQuery reportQuery = new ReportQuery(desc.getJavaClass(), builder);
reportQuery.setDescriptor(desc);
reportQuery.setShouldRetrieveFirstPrimaryKey(true);
reportQuery.setSelectionCriteria(whereClause);
reportQuery.setSession(getSession());
SQLSelectStatement selectStatement = ((ExpressionQueryMechanism)reportQuery.getQueryMechanism()).buildReportQuerySelectStatement(false, useCustomaryInheritanceExpression, inheritanceExpression, shouldUseAdditionalJoinExpression);
reportQuery.setSession(null);
return selectStatement;
}
protected SQLSelectStatement createSQLSelectStatementForAssignedExpressionForUpdateAll(Expression value)
{
ReportQuery reportQuery = new ReportQuery(getQuery().getReferenceClass(), value.getBuilder());
reportQuery.setDescriptor(getQuery().getDescriptor());
reportQuery.setSession(getSession());
reportQuery.addAttribute("", value);
SQLSelectStatement selectStatement = ((ExpressionQueryMechanism)reportQuery.getQueryMechanism()).buildReportQuerySelectStatement(false);
reportQuery.setSession(null);
return selectStatement;
}
/**
* This method return the clones of the list of expressions.
*/
private List cloneExpressions(List originalExpressions, Map clonedExpressions){
if ((originalExpressions == null) || (originalExpressions.isEmpty()) || (clonedExpressions == null)) {
return originalExpressions;
}
List newExpressions = new ArrayList<>(originalExpressions.size());
for (Expression expression : originalExpressions) {
newExpressions.add(expression.copiedVersionFrom(clonedExpressions));
}
return newExpressions;
}
/**
* Pre-build the SQL statement from the expression.
*/
@Override
public void prepareDeleteObject() {
ClassDescriptor descriptor = getDescriptor();
if (descriptor.usesFieldLocking() && (getTranslationRow() == null)) {
return;
}
// Add and prepare to a call a delete statement for each table.
// In the case of multiple tables, build the sql statements Vector in insert order. When the
// actual SQL calls are sent they are sent in the reverse of this order.
for (DatabaseTable table : descriptor.getMultipleTableInsertOrder()) {
SQLDeleteStatement deleteStatement = buildDeleteStatement(table);
if (descriptor.getTables().size() > 1) {
getSQLStatements().add(deleteStatement);
} else {
setSQLStatement(deleteStatement);
}
// Most databases support delete cascade constraints by specifying a ON DELETE CASCADE option when defining foreign key constraints.
// However some databases which don't support foreign key constraints cannot use delete cascade constraints.
// Therefore each delete operation should be executed in such a database platform instead of delegating delete cascade constraints.
boolean supportForeignKeyConstraints = getSession().getPlatform().supportsForeignKeyConstraints();
boolean supportCascadeOnDelete = supportForeignKeyConstraints && descriptor.isCascadeOnDeleteSetOnDatabaseOnSecondaryTables();
if (supportCascadeOnDelete) {
break;
}
}
super.prepareDeleteObject();
}
/**
* Pre-build the SQL statement from the expression.
*/
@Override
public void prepareDoesExist(DatabaseField field) {
setSQLStatement(buildSelectStatementForDoesExist(field));
super.prepareDoesExist(field);
}
/**
* Pre-build the SQL statement from the expression.
*/
@Override
public void prepareInsertObject() {
// Require modify row to prepare.
if (getModifyRow() == null) {
return;
}
// Add and prepare to a call a update statement for each table.
// In the case of multiple tables, build the sql statements in insert order.
ClassDescriptor descriptor = getDescriptor();
if (descriptor.getTables().size() == 1) {
setSQLStatement(buildInsertStatement(descriptor.getTables().get(0)));
} else {
for (DatabaseTable table : descriptor.getMultipleTableInsertOrder()) {
SQLInsertStatement insertStatement = buildInsertStatement(table);
getSQLStatements().add(insertStatement);
}
}
super.prepareInsertObject();
}
/**
* Pre-build the SQL statement from the expression.
*/
@Override
public void prepareReportQuerySelectAllRows() {
SQLSelectStatement statement = buildReportQuerySelectStatement(false);
setSQLStatement(statement);
setCallFromStatement();
// The statement is no longer require so can be released.
setSQLStatement(null);
getCall().returnManyRows();
prepareCall();
}
/**
* Pre-build the SQL statement from the expression.
* This is used for subselects, so does not normalize or generate the SQL as it needs the outer expression for this.
*/
@Override
public void prepareReportQuerySubSelect() {
setSQLStatement(buildReportQuerySelectStatement(true));
// The expression is no longer require so can be released.
setSelectionCriteria(null);
}
/**
* Pre-build the SQL statement from the expression.
*/
@Override
public void prepareSelectAllRows() {
// Check for multiple table inheritance which may require multiple queries.
if (!getDescriptor().hasInheritance() || !getDescriptor().getInheritancePolicy().requiresMultipleTableSubclassRead()){
setSQLStatement(buildNormalSelectStatement());
super.prepareSelectAllRows();
} else {
InheritancePolicy policy = getDescriptor().getInheritancePolicy();
if (policy.hasView()){
// CR#3158703 if the descriptor has a view, then it requires a single select,
// so can be prepared.
setSQLStatement(getDescriptor().getInheritancePolicy().buildViewSelectStatement((ObjectLevelReadQuery)getQuery()));
super.prepareSelectAllRows();
} else if ( ((ObjectLevelReadQuery)getQuery()).shouldOuterJoinSubclasses() ){
//outer join into a single select that can be built normally
setSQLStatement(buildNormalSelectStatement());
super.prepareSelectAllRows();
} else if (!getDescriptor().getInheritancePolicy().hasClassExtractor()) {
// CR#3158703 otherwise if using a type indicator at least the type select can be prepared.
setSQLStatement(getDescriptor().getInheritancePolicy().buildClassIndicatorSelectStatement((ObjectLevelReadQuery)getQuery()));
super.prepareSelectAllRows();
}
}
}
/**
* Pre-build the SQL statement from the expression.
*/
@Override
public void prepareSelectOneRow() {
// Check for multiple table inheritance which may require multiple queries.
if (!getDescriptor().hasInheritance() || !getDescriptor().getInheritancePolicy().requiresMultipleTableSubclassRead()){
setSQLStatement(buildNormalSelectStatement());
super.prepareSelectOneRow();
} else {
InheritancePolicy policy = getDescriptor().getInheritancePolicy();
if (policy.hasView()){
// CR#3158703 if the descriptor has a view, then it requires a single select,
// so can be prepared.
setSQLStatement(getDescriptor().getInheritancePolicy().buildViewSelectStatement((ObjectLevelReadQuery)getQuery()));
super.prepareSelectOneRow();
} else if ( ((ObjectLevelReadQuery)getQuery()).shouldOuterJoinSubclasses() ){
//outer join into a single select that can be built normally
setSQLStatement(buildNormalSelectStatement());
super.prepareSelectOneRow();
} else if (!getDescriptor().getInheritancePolicy().hasClassExtractor()) {
// CR#3158703 otherwise if using a type indicator at least the type select can be prepared.
setSQLStatement(getDescriptor().getInheritancePolicy().buildClassIndicatorSelectStatement((ObjectLevelReadQuery)getQuery()));
super.prepareSelectOneRow();
}
}
}
/**
* Pre-build the SQL statement from the expression.
*/
@Override
public void prepareUpdateObject() {
// Require modify row to prepare.
if (getModifyRow() == null) {
return;
}
// EL Bug 319759
AbstractRecord row = getQuery().getTranslationRow();
boolean useCache = (row == null || !(getQuery().shouldValidateUpdateCallCacheUse() && row.hasNullValueInFields()));
// PERF: Check the descriptor update SQL call cache for a matching update with the same fields.
List updateCalls = getDescriptor().getQueryManager().getCachedUpdateCalls(getModifyRow().getFields());
// If the calls were cached then don't need to prepare.
if (updateCalls != null && useCache == true) {
int updateCallsSize = updateCalls.size();
if (updateCallsSize == 1) {
// clone call, to be able to set query on clone
DatasourceCall existingCall = updateCalls.get(0);
DatasourceCall clonedCall = existingCall.clone();
setCall(clonedCall);
} else {
// clone calls
List clonedCalls = new ArrayList<>(updateCallsSize);
for (int i = 0; i < updateCallsSize; i++) {
DatasourceCall existingCall = updateCalls.get(i);
clonedCalls.add(existingCall.clone());
}
setCalls(clonedCalls);
}
return;
}
// Add and prepare to a call a update statement for each table.
int tablesSize = getDescriptor().getTables().size();
for (int index = 0; index < tablesSize; index++) {
DatabaseTable table = getDescriptor().getTables().get(index);
SQLUpdateStatement updateStatement = buildUpdateStatement(table);
if (tablesSize > 1) {
getSQLStatements().add(updateStatement);
} else {
setSQLStatement(updateStatement);
}
}
super.prepareUpdateObject();
// PERF: Cache the update SQL call to avoid regeneration.
if (useCache == true) { // EL Bug 319759
if (hasMultipleCalls()) {
updateCalls = getCalls();
} else {
updateCalls = new ArrayList<>(1);
if (getCall() != null) {
updateCalls.add(getCall());
}
}
getDescriptor().getQueryManager().putCachedUpdateCalls(getModifyRow().getFields(), updateCalls);
}
}
private boolean isFieldInUpdate(Expression writeLock, HashMap updateClauses) {
if (!(writeLock instanceof FieldExpression fe)) {
return false;
}
final DatabaseField targetField = fe.getField();
final Set keys = updateClauses.keySet();
for (Object key : keys) {
if (!(key instanceof QueryKeyExpression qke)) {
continue;
}
DatabaseField qkField = getDescriptor().getObjectBuilder().getFieldForQueryKeyName(qke.getName());
if (qkField == targetField) {
return true;
}
}
return false;
}
/**
* Pre-build the SQL statement from the expressions.
*/
@Override
public void prepareUpdateAll() {
ExpressionBuilder builder = ((UpdateAllQuery)getQuery()).getExpressionBuilder();
HashMap updateClauses = ((UpdateAllQuery)getQuery()).getUpdateClauses();
boolean updateClausesHasBeenCloned = false;
// Add a statement to update the optimistic locking field if their is one.
OptimisticLockingPolicy policy = getDescriptor().getOptimisticLockingPolicy();
if (policy != null) {
if(policy.getWriteLockField() != null) {
Expression writeLock = builder.getField(policy.getWriteLockField());
// Note: The spec allows for version fields to be updated in bulk updates. Adding the writeLockUpdateExpression when there is already
// a QueryKeyExpression associated with the version column will result in a scenario where one wins out by virtue of order of iteration
// of updateClauses's entrySet. So we need to check the updateClause to see if the database fields in the writeLock expression are
// already targeted for update.
if (!isFieldInUpdate(writeLock, updateClauses)) {
Expression writeLockUpdateExpression = policy.getWriteLockUpdateExpression(builder, getQuery().getSession());
if (writeLockUpdateExpression != null) {
// clone it to keep user's original data intact
updateClauses = (HashMap)updateClauses.clone();
updateClausesHasBeenCloned = true;
updateClauses.put(writeLock, writeLockUpdateExpression);
}
}
}
}
if (getDescriptor().hasSerializedObjectPolicy()) {
if (!updateClausesHasBeenCloned) {
// clone it to keep user's original data intact
updateClauses = (HashMap)updateClauses.clone();
updateClausesHasBeenCloned = true;
}
Expression sopFieldExpression = builder.getField(getDescriptor().getSerializedObjectPolicy().getField());
updateClauses.put(sopFieldExpression, new ConstantExpression(null, sopFieldExpression));
}
Map> tables_databaseFieldsToValues = new HashMap<>();
Map> tablesToPrimaryKeyFields = new HashMap<>();
Iterator it = updateClauses.entrySet().iterator();
while(it.hasNext()) {
Map.Entry entry = (Map.Entry)it.next();
Object fieldObject = entry.getKey();
DataExpression fieldExpression = null;
Expression baseExpression = null; // QueryKeyExpression or FieldExpression of the field
String attributeName = null;
if(fieldObject instanceof String) {
attributeName = (String)fieldObject;
} else {
// it should be either QueryKeyExpression or FieldExpression
fieldExpression = (DataExpression)fieldObject;
}
DatabaseField field = null;
DatabaseMapping mapping = null;
if(attributeName != null) {
mapping = getDescriptor().getObjectBuilder().getMappingForAttributeName(attributeName);
if (mapping != null && !mapping.getFields().isEmpty()) {
field = mapping.getFields().get(0);
}
if(field == null) {
throw QueryException.updateAllQueryAddUpdateDoesNotDefineField(getDescriptor(), getQuery(), attributeName);
}
baseExpression = ((UpdateAllQuery)getQuery()).getExpressionBuilder().get(attributeName);
} else if (fieldExpression != null) {
// it should be either QueryKeyExpression or ExpressionBuilder
if (fieldExpression.getBaseExpression() instanceof ExpressionBuilder) {
field = getDescriptor().getObjectBuilder().getFieldForQueryKeyName(fieldExpression.getName());
}
if(field == null) {
DataExpression fieldExpressionClone = (DataExpression)fieldExpression.clone();
fieldExpressionClone.getBuilder().setQueryClass(getQuery().getReferenceClass());
fieldExpressionClone.getBuilder().setSession(getSession().getRootSession(null));
field = fieldExpressionClone.getField();
if(field == null) {
throw QueryException.updateAllQueryAddUpdateDoesNotDefineField(getDescriptor(), getQuery(), fieldExpression.toString());
}
}
mapping = getDescriptor().getObjectBuilder().getMappingForField(field);
baseExpression = fieldExpression;
}
Object valueObject = entry.getValue();
List fields;
List