/**
* 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;
}
/**
* Return an expression that allows you to treat its base as if it were a subclass of the class
* returned by the base This can only be called on an ExpressionBuilder, the result of
* expression.get(String), expression.getAllowingNull(String), the result of
* expression.anyOf("String") or the result of expression.anyOfAllowingNull("String")
*
* <p>downcast uses Expression.type() internally to guarantee the results are of the specified
* class.
*
* <p>Example:
*
* <pre><blockquote>
* Expression: employee.get("project").as(LargeProject.class).get("budget").equal(1000)
* Java: ((LargeProject)employee.getProjects().get(0)).getBudget() == 1000
* SQL: LPROJ.PROJ_ID (+)= PROJ.PROJ_ID AND L_PROJ.BUDGET = 1000 AND PROJ.TYPE = "L"
* </blockquote></pre>
*/
@Override
public Expression treat(Class castClass) {
// to be used on expressionBuilders
QueryKeyExpression clonedExpression = new TreatAsExpression(castClass, this);
clonedExpression.shouldQueryToManyRelationship = false;
clonedExpression.hasQueryKey = false;
clonedExpression.hasMapping = false;
this.addDerivedExpression(clonedExpression);
return clonedExpression;
}
/**
* PUBLIC: Return an expression representing traversal of a 1:many or many:many relationship. This
* allows you to query whether any of the "many" side of the relationship satisfies the remaining
* criteria.
*
* <p>Example:
*
* <pre><blockquote>
* Expression: employee.anyOf("managedEmployees").get("firstName").equal("Bob")
* Java: no direct equivalent
* SQL: SELECT DISTINCT ... WHERE (t2.MGR_ID = t1.ID) AND (t2.F_NAME = 'Bob')
* </pre>
*
* </blockquote>
*
* @parameter shouldJoinBeIndependent indicates whether a new expression should be created.
*/
@Override
public Expression anyOf(String attributeName, boolean shouldJoinBeIndependent) {
QueryKeyExpression queryKey;
if (shouldJoinBeIndependent) {
queryKey = newDerivedExpressionNamed(attributeName);
} else {
queryKey = derivedExpressionNamed(attributeName);
}
queryKey.doQueryToManyRelationship();
return queryKey;
}
/**
* INTERNAL: Return if the expression is equal to the other. This is used to allow dynamic
* expression's SQL to be cached.
*/
public boolean equals(Object object) {
if (this == object) {
return true;
}
if (!super.equals(object)) {
return false;
}
QueryKeyExpression expression = (QueryKeyExpression) object;
// Return false for anyOf expressions, as equality is unknown.
if (shouldQueryToManyRelationship() || expression.shouldQueryToManyRelationship()) {
return false;
}
return ((getName() == expression.getName())
|| ((getName() != null) && getName().equals(expression.getName())));
}
/**
* 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;
}
public QueryKeyExpression existingDerivedExpressionNamed(String attributeName) {
if (this.derivedExpressions == null) {
return null;
}
List<Expression> derivedExpressionsCopy;
synchronized (this) {
derivedExpressionsCopy = new ArrayList(this.derivedExpressions);
}
for (Expression derivedExpression : derivedExpressionsCopy) {
QueryKeyExpression exp = (QueryKeyExpression) derivedExpression;
if (exp.getName().equals(attributeName)) {
return exp;
}
}
return null;
}
/** INTERNAL: Return if the attribute is specified for batch reading. */
public boolean isAttributeBatchRead(String attributeName) {
if (!hasBatchReadAttributes()) {
return false;
}
Vector batchReadAttributeExpressions = getBatchReadAttributeExpressions();
int size = batchReadAttributeExpressions.size();
for (int index = 0; index < size; index++) {
QueryKeyExpression expression = (QueryKeyExpression) batchReadAttributeExpressions.get(index);
while (!expression.getBaseExpression().isExpressionBuilder()) {
expression = (QueryKeyExpression) expression.getBaseExpression();
}
if (expression.getName().equals(attributeName)) {
return true;
}
}
return false;
}