SubsetNode.cs

Go to the documentation of this file.

// 
//  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.Tables;

namespace Deveel.Data.Sql.Query {
    [Serializable]
    class SubsetNode : SingleQueryPlanNode {
        public SubsetNode(IQueryPlanNode child, ObjectName[] originalColumnNames, ObjectName[] aliasColumnNames) 
            : base(child) {
            OriginalColumnNames = originalColumnNames;
            AliasColumnNames = aliasColumnNames;
        }

        private SubsetNode(ObjectData data)
            : base(data) {
            OriginalColumnNames = data.GetValue<ObjectName[]>("OriginalColumns");
            AliasColumnNames = data.GetValue<ObjectName[]>("AliasColumns");
        }

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

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

        public override ITable Evaluate(IRequest context) {
            var table = Child.Evaluate(context);
            return table.Subset(OriginalColumnNames, AliasColumnNames);
        }

        public void SetAliasParentName(ObjectName parentName) {
            var aliases = new ObjectName[AliasColumnNames.Length];
            for (int i = 0; i < aliases.Length; i++) {
                aliases[i] = new ObjectName(parentName, aliases[i].Name);
            }

            AliasColumnNames = aliases;
        }

        protected override void GetData(SerializeData data) {
            data.SetValue("OriginalColumns", OriginalColumnNames);
            data.SetValue("AliasColumns", AliasColumnNames);
        }
    }
}