public HomogenousMap Execute()
        {
            ISQLDatabase database    = ServiceRegistration.Get <ISQLDatabase>();
            ITransaction transaction = database.BeginTransaction();

            try
            {
                using (IDbCommand command = transaction.CreateCommand())
                {
                    string          valueAlias;
                    string          groupSizeAlias;
                    string          statementStr;
                    IList <BindVar> bindVars;
                    if (_selectAttribute.Cardinality == Cardinality.Inline || _selectAttribute.Cardinality == Cardinality.ManyToOne)
                    {
                        QueryAttribute   selectAttributeQA = new QueryAttribute(_selectAttribute);
                        MainQueryBuilder builder           = new MainQueryBuilder(_miaManagement,
                                                                                  new QueryAttribute[] { selectAttributeQA }, _selectProjectionFunction,
                                                                                  _necessaryRequestedMIATypes, new MediaItemAspectMetadata[] {}, _filter, null);
                        IDictionary <QueryAttribute, string> qa2a;
                        builder.GenerateSqlGroupByStatement(out groupSizeAlias, out qa2a, out statementStr, out bindVars);
                        valueAlias = qa2a[selectAttributeQA];
                    }
                    else
                    {
                        ComplexAttributeQueryBuilder builder = new ComplexAttributeQueryBuilder(_miaManagement, _selectAttribute,
                                                                                                _selectProjectionFunction, _necessaryRequestedMIATypes, _filter);
                        builder.GenerateSqlGroupByStatement(_selectAttributeFilter, out valueAlias, out groupSizeAlias,
                                                            out statementStr, out bindVars);
                    }
                    command.CommandText = statementStr;
                    foreach (BindVar bindVar in bindVars)
                    {
                        database.AddParameter(command, bindVar.Name, bindVar.Value, bindVar.VariableType);
                    }

                    Type          valueType = _projectionValueType ?? _selectAttribute.AttributeType;
                    HomogenousMap result    = new HomogenousMap(valueType, typeof(int));
                    using (IDataReader reader = command.ExecuteReader())
                    {
                        int valueCol     = reader.GetOrdinal(valueAlias);
                        int groupSizeCol = reader.GetOrdinal(groupSizeAlias);
                        while (reader.Read())
                        {
                            result.Add(database.ReadDBValue(valueType, reader, valueCol),
                                       database.ReadDBValue <int>(reader, groupSizeCol));
                        }
                    }
                    return(result);
                }
            }
            finally
            {
                transaction.Dispose();
            }
        }
    public HomogenousMap Execute()
    {
      ISQLDatabase database = ServiceRegistration.Get<ISQLDatabase>();
      ITransaction transaction = database.BeginTransaction();
      try
      {
        using (IDbCommand command = transaction.CreateCommand())
        {
          string valueAlias;
          string groupSizeAlias;
          string statementStr;
          IList<BindVar> bindVars;
          if (_selectAttribute.Cardinality == Cardinality.Inline || _selectAttribute.Cardinality == Cardinality.ManyToOne)
          {
            QueryAttribute selectAttributeQA = new QueryAttribute(_selectAttribute);
            MainQueryBuilder builder = new MainQueryBuilder(_miaManagement,
                new QueryAttribute[] {selectAttributeQA}, _selectProjectionFunction,
                _necessaryRequestedMIATypes, new MediaItemAspectMetadata[] {}, _filter, null);
            IDictionary<QueryAttribute, string> qa2a;
            builder.GenerateSqlGroupByStatement(out groupSizeAlias, out qa2a, out statementStr, out bindVars);
            valueAlias = qa2a[selectAttributeQA];
          }
          else
          {
            ComplexAttributeQueryBuilder builder = new ComplexAttributeQueryBuilder(_miaManagement, _selectAttribute,
                _selectProjectionFunction, _necessaryRequestedMIATypes, _filter);
            builder.GenerateSqlGroupByStatement(_selectAttributeFilter, out valueAlias, out groupSizeAlias,
                out statementStr, out bindVars);
          }
          command.CommandText = statementStr;
          foreach (BindVar bindVar in bindVars)
            database.AddParameter(command, bindVar.Name, bindVar.Value, bindVar.VariableType);

          Type valueType = _projectionValueType ?? _selectAttribute.AttributeType;
          HomogenousMap result = new HomogenousMap(valueType, typeof(int));
          using (IDataReader reader = command.ExecuteReader())
          {
            int valueCol = reader.GetOrdinal(valueAlias);
            int groupSizeCol = reader.GetOrdinal(groupSizeAlias);
            while (reader.Read())
              result.Add(database.ReadDBValue(valueType, reader, valueCol),
                  database.ReadDBValue<int>(reader, groupSizeCol));
          }
          return result;
        }
      }
      finally
      {
        transaction.Dispose();
      }
    }
        public Tuple <HomogenousMap, HomogenousMap> Execute()
        {
            ISQLDatabase database    = ServiceRegistration.Get <ISQLDatabase>();
            ITransaction transaction = database.BeginTransaction();

            try
            {
                using (IDbCommand command = transaction.CreateCommand())
                {
                    string          keyAlias       = null;
                    string          valueAlias     = null;
                    string          groupSizeAlias = null;
                    string          statementStr   = null;
                    IList <BindVar> bindVars       = null;
                    if (_selectValueAttribute.Cardinality == Cardinality.Inline || _selectValueAttribute.Cardinality == Cardinality.ManyToOne)
                    {
                        List <QueryAttribute> qAttributes            = new List <QueryAttribute>();
                        QueryAttribute        selectValueAttributeQA = new QueryAttribute(_selectValueAttribute);
                        qAttributes.Add(selectValueAttributeQA);
                        QueryAttribute selectKeyAttributeQA = null;
                        if (_selectKeyAttribute != null)
                        {
                            selectKeyAttributeQA = new QueryAttribute(_selectKeyAttribute);
                            qAttributes.Add(selectKeyAttributeQA);
                        }
                        MIAQueryBuilder builder = new MIAQueryBuilder(_miaManagement, qAttributes, _selectProjectionFunction,
                                                                      _necessaryRequestedMIATypes, new MediaItemAspectMetadata[] {}, _filter, _subqueryFilter, null);
                        IDictionary <QueryAttribute, string> qa2a;
                        builder.GenerateSqlGroupByStatement(out groupSizeAlias, out qa2a, out statementStr, out bindVars);
                        valueAlias = qa2a[selectValueAttributeQA];
                        if (_selectKeyAttribute != null)
                        {
                            keyAlias = qa2a[selectKeyAttributeQA];
                        }
                    }
                    else
                    {
                        if (_selectKeyAttribute != null)
                        {
                            throw new InvalidDataException("Value attribute '{0}' does not support key value grouping", _selectValueAttribute.AttributeName);
                        }
                        ComplexAttributeQueryBuilder builder = new ComplexAttributeQueryBuilder(_miaManagement, _selectValueAttribute,
                                                                                                _selectProjectionFunction, _necessaryRequestedMIATypes, _filter, _subqueryFilter);
                        builder.GenerateSqlGroupByStatement(_selectAttributeFilter, out valueAlias, out groupSizeAlias,
                                                            out statementStr, out bindVars);
                    }
                    command.CommandText = statementStr;
                    foreach (BindVar bindVar in bindVars)
                    {
                        database.AddParameter(command, bindVar.Name, bindVar.Value, bindVar.VariableType);
                    }

                    Tuple <HomogenousMap, HomogenousMap> result = null;
                    if (_selectKeyAttribute != null)
                    {
                        Type          valueType = _projectionValueType ?? _selectValueAttribute.AttributeType;
                        Type          keyType   = _selectKeyAttribute.AttributeType;
                        HomogenousMap valueMap  = new HomogenousMap(valueType, typeof(int));
                        HomogenousMap keyMap    = new HomogenousMap(valueType, keyType);
                        using (IDataReader reader = command.ExecuteReader())
                        {
                            int keyCol       = reader.GetOrdinal(keyAlias);
                            int valueCol     = reader.GetOrdinal(valueAlias);
                            int groupSizeCol = reader.GetOrdinal(groupSizeAlias);
                            while (reader.Read())
                            {
                                if (!keyMap.ContainsKey(database.ReadDBValue(valueType, reader, valueCol)))
                                {
                                    keyMap.Add(database.ReadDBValue(valueType, reader, valueCol), database.ReadDBValue(keyType, reader, keyCol));
                                    valueMap.Add(database.ReadDBValue(valueType, reader, valueCol), database.ReadDBValue <int>(reader, groupSizeCol));
                                }
                            }
                        }
                        result = new Tuple <HomogenousMap, HomogenousMap>(valueMap, keyMap);
                    }
                    else
                    {
                        Type          valueType = _projectionValueType ?? _selectValueAttribute.AttributeType;
                        HomogenousMap valueMap  = new HomogenousMap(valueType, typeof(int));
                        using (IDataReader reader = command.ExecuteReader())
                        {
                            int valueCol     = reader.GetOrdinal(valueAlias);
                            int groupSizeCol = reader.GetOrdinal(groupSizeAlias);
                            while (reader.Read())
                            {
                                valueMap.Add(database.ReadDBValue(valueType, reader, valueCol),
                                             database.ReadDBValue <int>(reader, groupSizeCol));
                            }
                        }
                        result = new Tuple <HomogenousMap, HomogenousMap>(valueMap, null);
                    }
                    return(result);
                }
            }
            finally
            {
                transaction.Dispose();
            }
        }