GroupNode.cs

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// 
//  Copyright 2010-2015 Deveel
// 
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
// 
//        http://www.apache.org/licenses/LICENSE-2.0
// 
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.
//

using System;

using Deveel.Data.Serialization;
using Deveel.Data.Sql.Expressions;
using Deveel.Data.Sql.Tables;

namespace Deveel.Data.Sql.Query {
    [Serializable]
    class GroupNode : SingleQueryPlanNode {
        public GroupNode(IQueryPlanNode child, ObjectName groupMaxColumn, SqlExpression[] functions, string[] names) 
            : this(child, new ObjectName[0], groupMaxColumn, functions, names) {
        }

        public GroupNode(IQueryPlanNode child, ObjectName[] columnNames, ObjectName groupMaxColumn, SqlExpression[] functions, string[] names) : base(child) {
            ColumnNames = columnNames;
            GroupMaxColumn = groupMaxColumn;
            Functions = functions;
            Names = names;
        }

        private GroupNode(ObjectData data)
            : base(data) {
            ColumnNames = data.GetValue<ObjectName[]>("Columns");
            GroupMaxColumn = data.GetValue<ObjectName>("GroupMax");
            Functions = data.GetValue<SqlExpression[]>("Functions");
            Names = data.GetValue<string[]>("Names");
        }

        public ObjectName[] ColumnNames { get; private set; }

        public ObjectName GroupMaxColumn { get; private set; }

        public SqlExpression[] Functions { get; private set; }

        public string[] Names { get; private set; }

        protected override void GetData(SerializeData data) {
            data.SetValue("Columns", ColumnNames);
            data.SetValue("GroupMax", GroupMaxColumn);
            data.SetValue("Functions", Functions);
            data.SetValue("Names", Names);
        }

        public override ITable Evaluate(IRequest context) {
            var childTable = Child.Evaluate(context);
            var funTable = new FunctionTable(childTable, Functions, Names, context);

            // If no columns then it is implied the whole table is the group.
            if (ColumnNames == null) {
                funTable = funTable.AsGroup();
            } else {
                funTable = funTable.CreateGroupMatrix(ColumnNames);
            }

            return funTable.MergeWith(GroupMaxColumn);
        }
    }
}