/**
* INTERNAL: This method is used when computing the nested queries for batch read mappings. It
* recurses computing the nested mapping queries.
*/
protected void computeNestedQueriesForBatchReadExpressions(Vector batchReadExpressions) {
for (int index = 0; index < batchReadExpressions.size(); index++) {
ObjectExpression objectExpression = (ObjectExpression) batchReadExpressions.get(index);
// Expression may not have been initialized.
ExpressionBuilder builder = objectExpression.getBuilder();
builder.setSession(getSession().getRootSession(null));
builder.setQueryClass(getReferenceClass());
// PERF: Cache join attribute names.
ObjectExpression baseExpression = objectExpression;
while (!baseExpression.getBaseExpression().isExpressionBuilder()) {
baseExpression = (ObjectExpression) baseExpression.getBaseExpression();
}
this.batchReadAttributes.add(baseExpression.getName());
// Ignore nested
if (objectExpression.getBaseExpression().isExpressionBuilder()) {
DatabaseMapping mapping = objectExpression.getMapping();
if ((mapping != null) && mapping.isForeignReferenceMapping()) {
// A nested query must be built to pass to the descriptor that looks like the real query
// execution would.
ReadQuery nestedQuery = ((ForeignReferenceMapping) mapping).prepareNestedBatchQuery(this);
// Register the nested query to be used by the mapping for all the objects.
getBatchReadMappingQueries().put(mapping, nestedQuery);
}
}
}
}
/**
* INTERNAL: Parses an expression to return the first non-AggregateObjectMapping expression after
* the base ExpressionBuilder. This is used by joining and batch fetch to get the list of mappings
* that really need to be processed (non-aggregates).
*
* @param aggregateMappingsEncountered - collection of aggregateObjectMapping expressions
* encountered in the returned expression between the first expression and the
* ExpressionBuilder
* @return first non-AggregateObjectMapping expression after the base ExpressionBuilder from the
* fullExpression
*/
public ObjectExpression getFirstNonAggregateExpressionAfterExpressionBuilder(
List aggregateMappingsEncountered) {
boolean done = false;
ObjectExpression baseExpression = this;
ObjectExpression prevExpression = this;
while (!baseExpression.getBaseExpression().isExpressionBuilder() && !done) {
baseExpression = (ObjectExpression) baseExpression.getBaseExpression();
while (!baseExpression.isExpressionBuilder()
&& baseExpression.getMapping().isAggregateObjectMapping()) {
aggregateMappingsEncountered.add(baseExpression.getMapping());
baseExpression = (ObjectExpression) baseExpression.getBaseExpression();
}
if (baseExpression.isExpressionBuilder()) {
done = true;
// use the one closest to the expression builder that wasn't an aggregate
baseExpression = prevExpression;
} else {
prevExpression = baseExpression;
}
}
return baseExpression;
}
