private object ExecuteAggregateQuery(QueryContextsEntry queryContextsEntry, string field, AggregateType aggregateType)
{
Type t = queryContextsEntry.Type;
IQueryGenerator queryGenerator = ConfigContainer.Resolve <IQueryGenerator>();
string generatedQuery = queryGenerator.GenerateAggregateQueryString(field, queryContextsEntry, this.expressionTree, this.queryContextsForTypes.Count > 1, aggregateType);
using (IPersistenceHandler persistenceHandler = this.pm.PersistenceHandlerManager.GetPersistenceHandler(t))
{
persistenceHandler.VerboseMode = this.pm.VerboseMode;
persistenceHandler.LogAdapter = this.pm.LogAdapter;
this.pm.CheckTransaction(persistenceHandler, t);
// Note, that we can't execute all subQueries in one batch, because
// the subqueries could be executed against different connections.
// TODO: This could be optimized, if we made clear whether the involved tables
// can be reached with the same connection.
var l = persistenceHandler.ExecuteBatch(new string[] { generatedQuery }, this.parameters);
if (l.Count == 0)
{
return(null);
}
return((l[0])["AggrResult"]);
}
}
