// i.e. when the linked element maps to the same table as the container mapping
sourceFieldSteps = XPath.steps(root, sourceField, namespaces);
}
// a nested feature
if (isJoining() && isJDBC) {
attMapping = new JoiningNestedAttributeMapping(idExpression, sourceExpression,
targetXPathSteps, isMultiValued, clientProperties, elementExpr,
sourceFieldSteps, namespaces);
} else {
attMapping = new NestedAttributeMapping(idExpression, sourceExpression,
targetXPathSteps, isMultiValued, clientProperties, elementExpr,