/*
* INTERNAL:
* If this query key represents a foreign reference answer the
* base expression -> foreign reference join criteria.
*/
public Expression mappingCriteria() {
Expression selectionCriteria;
// First look for a query key, then a mapping
if (getQueryKeyOrNull() == null) {
if ((getMapping() == null) || (!getMapping().isForeignReferenceMapping())) {
return null;
} else {
// The join criteria is now twisted by the mappings.
selectionCriteria = ((ForeignReferenceMapping) getMapping()).getJoinCriteria(this);
}
} else {
if (!getQueryKeyOrNull().isForeignReferenceQueryKey()) {
return null;
} else {
selectionCriteria = ((ForeignReferenceQueryKey) getQueryKeyOrNull()).getJoinCriteria();
selectionCriteria = getBaseExpression().twist(selectionCriteria, this);
}
}
if (shouldUseOuterJoin() && getSession().getPlatform().shouldPrintOuterJoinInWhereClause()) {
selectionCriteria = selectionCriteria.convertToUseOuterJoin();
}
return selectionCriteria;
}
/**
* INTERNAL: Rebuild myself against the base, with the values of parameters supplied by the
* context expression. This is used for transforming a standalone expression (e.g. the join
* criteria of a mapping) into part of some larger expression. You normally would not call this
* directly, instead calling twist See the comment there for more details"
*/
public Expression twistedForBaseAndContext(Expression newBase, Expression context) {
Expression twistedBase = getBaseExpression().twistedForBaseAndContext(newBase, context);
QueryKeyExpression result = (QueryKeyExpression) twistedBase.get(getName());
if (shouldUseOuterJoin) {
result.doUseOuterJoin();
}
if (shouldQueryToManyRelationship) {
result.doQueryToManyRelationship();
}
return result;
}
/**
* INTERNAL: This expression is built on a different base than the one we want. Rebuild it and
* return the root of the new tree
*/
public Expression rebuildOn(Expression newBase) {
Expression newLocalBase = getBaseExpression().rebuildOn(newBase);
QueryKeyExpression result = null;
// For bug 3096634 rebuild outer joins correctly from the start.
if (shouldUseOuterJoin) {
result = (QueryKeyExpression) newLocalBase.getAllowingNull(getName());
} else {
result = (QueryKeyExpression) newLocalBase.get(getName());
}
if (shouldQueryToManyRelationship) {
result.doQueryToManyRelationship();
}
result.setSelectIfOrderedBy(selectIfOrderedBy());
return result;
}
/**
* INTERNAL: Return the expression to join the main table of this node to any auxiliary tables.
*/
public Expression additionalExpressionCriteria() {
if (getDescriptor() == null) {
return null;
}
Expression criteria = getDescriptor().getQueryManager().getAdditionalJoinExpression();
if (criteria != null) {
criteria = getBaseExpression().twist(criteria, this);
if (shouldUseOuterJoin() && getSession().getPlatform().shouldPrintOuterJoinInWhereClause()) {
criteria.convertToUseOuterJoin();
}
}
if (getSession().getPlatform().shouldPrintOuterJoinInWhereClause()) {
if (isUsingOuterJoinForMultitableInheritance()) {
Expression childrenCriteria =
getDescriptor().getInheritancePolicy().getChildrenJoinExpression();
childrenCriteria = getBaseExpression().twist(childrenCriteria, this);
childrenCriteria.convertToUseOuterJoin();
if (criteria == null) {
criteria = childrenCriteria;
} else {
criteria = criteria.and(childrenCriteria);
}
}
}
if ((getDescriptor() != null) && (getDescriptor().getHistoryPolicy() != null)) {
Expression historyCriteria =
getDescriptor().getHistoryPolicy().additionalHistoryExpression(this);
if (criteria != null) {
criteria = criteria.and(historyCriteria);
} else {
criteria = historyCriteria;
}
}
return criteria;
}
/**
* INTERNAL: For CR#2456 if this is part of an objExp.equal(objExp), do not need to add additional
* expressions to normalizer both times, and the foreign key join replaces the equal expression.
*/
public Expression normalize(ExpressionNormalizer normalizer, Vector foreignKeyJoinPointer) {
if (hasBeenNormalized()) {
return this;
}
super.normalize(normalizer);
setHasBeenNormalized(true);
if ((getMapping() != null) && getMapping().isDirectToXMLTypeMapping()) {
normalizer.getStatement().setRequiresAliases(true);
}
// Check if any joins need to be added.
if (isAttribute()) {
return this;
}
// If the mapping is 'ref' or 'structure', no join needed.
if ((getMapping() != null)
&& (getMapping().isReferenceMapping() || getMapping().isStructureMapping())) {
normalizer.getStatement().setRequiresAliases(true);
return this;
}
// Compute if a distinct is required during normalization.
if (shouldQueryToManyRelationship()
&& (!normalizer.getStatement().isDistinctComputed())
&& (!normalizer.getStatement().isAggregateSelect())) {
normalizer.getStatement().useDistinct();
}
// Turn off DISTINCT if nestedTableMapping is used (not supported by Oracle 8.1.5).
if ((getMapping() != null) && getMapping().isNestedTableMapping()) {
// There are two types of nested tables, one used by clients, one used by mappings, do nothing
// in the mapping case.
if (!shouldQueryToManyRelationship()) {
return this;
}
normalizer.getStatement().dontUseDistinct();
}
Expression mappingExpression = mappingCriteria();
if (mappingExpression != null) {
mappingExpression = mappingExpression.normalize(normalizer);
}
if (mappingExpression != null) {
// If the join was an outer join we must not add the join criteria to the where clause,
// if the platform prints the join in the from clause.
if (shouldUseOuterJoin() && (getSession().getPlatform().isInformixOuterJoin())) {
normalizer.getStatement().getOuterJoinExpressions().addElement(this);
normalizer.getStatement().getOuterJoinedMappingCriteria().addElement(mappingExpression);
normalizer.addAdditionalExpression(mappingExpression.and(additionalExpressionCriteria()));
return this;
} else if ((shouldUseOuterJoin() || isUsingOuterJoinForMultitableInheritance())
&& (!getSession().getPlatform().shouldPrintOuterJoinInWhereClause())) {
if (shouldUseOuterJoin()) {
normalizer.getStatement().getOuterJoinExpressions().addElement(this);
normalizer.getStatement().getOuterJoinedMappingCriteria().addElement(mappingExpression);
normalizer
.getStatement()
.getOuterJoinedAdditionalJoinCriteria()
.addElement(additionalExpressionCriteriaMap());
normalizer.getStatement().getDescriptorsForMultitableInheritanceOnly().add(null);
return this;
} else {
if (isUsingOuterJoinForMultitableInheritance()) {
normalizer.getStatement().getOuterJoinExpressions().addElement(null);
normalizer.getStatement().getOuterJoinedMappingCriteria().addElement(null);
normalizer
.getStatement()
.getOuterJoinedAdditionalJoinCriteria()
.addElement(additionalExpressionCriteriaMap());
normalizer
.getStatement()
.getDescriptorsForMultitableInheritanceOnly()
.add(getMapping().getReferenceDescriptor());
// fall through to the main case
}
}
}
// This must be added even if outer. Actually it should be converted to use a right outer
// join, but that gets complex
// so we do not support this current which is a limitation in some cases.
if (foreignKeyJoinPointer != null) {
// If this expression is right side of an objExp.equal(objExp), one
// need not add additionalExpressionCriteria twice.
// Also the join will replace the original objExp.equal(objExp).
// For CR#2456.
foreignKeyJoinPointer.add(mappingExpression);
} else {
normalizer.addAdditionalExpression(mappingExpression.and(additionalExpressionCriteria()));
}
}
// For bug 2900974 special code for DirectCollectionMappings moved to printSQL.
return this;
}
