private static void FlattenSubQuery(QueryModel queryModel, QueryModel subQueryModel, GroupResultOperator groupBy)
{
foreach (var resultOperator in queryModel.ResultOperators.Where(resultOperator => !AcceptableOuterResultOperators.Contains(resultOperator.GetType())))
{
throw new NotImplementedException("Cannot use group by with the " + resultOperator.GetType().Name + " result operator.");
}
// Move the result operator up.
SubQueryFromClauseFlattener.InsertResultOperators(subQueryModel.ResultOperators, queryModel);
for (var i = 0; i < queryModel.BodyClauses.Count; i++)
{
var clause = queryModel.BodyClauses[i];
clause.TransformExpressions(s => GroupBySelectClauseRewriter.ReWrite(s, groupBy, subQueryModel));
//all outer where clauses actually are having clauses
var whereClause = clause as WhereClause;
if (whereClause != null)
{
queryModel.BodyClauses.RemoveAt(i);
queryModel.BodyClauses.Insert(i, new NhHavingClause(whereClause.Predicate));
}
}
foreach (var bodyClause in subQueryModel.BodyClauses)
{
queryModel.BodyClauses.Add(bodyClause);
}
// Replace the outer select clause...
queryModel.SelectClause.TransformExpressions(s =>
GroupBySelectClauseRewriter.ReWrite(s, groupBy, subQueryModel));
// Point all query source references to the outer from clause
var visitor = new SwapQuerySourceVisitor(queryModel.MainFromClause, subQueryModel.MainFromClause);
queryModel.TransformExpressions(visitor.Swap);
// Replace the outer query source
queryModel.MainFromClause = subQueryModel.MainFromClause;
}
public static Expression ReWrite(Expression expression, GroupResultOperator groupBy, QueryModel model)
{
var visitor = new GroupBySelectClauseRewriter(groupBy, model);
return(TransparentIdentifierRemovingExpressionVisitor.ReplaceTransparentIdentifiers(visitor.Visit(expression)));
}