DeclareCursorStatement.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 System.Collections.Generic;
using System.IO;
using System.Linq;

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

namespace Deveel.Data.Sql.Statements {
    [Serializable]
    public sealed class DeclareCursorStatement : SqlStatement {
        public DeclareCursorStatement(string cursorName, SqlQueryExpression queryExpression) 
            : this(cursorName, null, queryExpression) {
        }

        public DeclareCursorStatement(string cursorName, IEnumerable<CursorParameter> parameters, SqlQueryExpression queryExpression) 
            : this(cursorName, parameters, CursorFlags.Insensitive, queryExpression) {
        }

        public DeclareCursorStatement(string cursorName, CursorFlags flags, SqlQueryExpression queryExpression) 
            : this(cursorName, null, flags, queryExpression) {
        }

        public DeclareCursorStatement(string cursorName, IEnumerable<CursorParameter> parameters, CursorFlags flags, SqlQueryExpression queryExpression) {
            if (queryExpression == null)
                throw new ArgumentNullException("queryExpression");
            if (String.IsNullOrEmpty(cursorName))
                throw new ArgumentNullException("cursorName");

            CursorName = cursorName;
            Parameters = parameters;
            Flags = flags;
            QueryExpression = queryExpression;
        }

        private DeclareCursorStatement(ObjectData data) {
            CursorName = data.GetString("CursorName");
            QueryExpression = data.GetValue<SqlQueryExpression>("QueryExpression");
            Flags = (CursorFlags) data.GetInt32("Flags");

            if (data.HasValue("Parameters")) {
                var parameters = data.GetValue<CursorParameter[]>("Parameters");
                Parameters = new List<CursorParameter>(parameters);
            }
        }

        public string CursorName { get; private set; }

        public SqlQueryExpression QueryExpression { get; private set; }

        public CursorFlags Flags { get; set; }

        public IEnumerable<CursorParameter> Parameters { get; set; }

        protected override void GetData(SerializeData data) {
            data.SetValue("CursorName", CursorName);
            data.SetValue("QueryExpression", QueryExpression);
            data.SetValue("Flags", (int)Flags);

            if (Parameters != null) {
                var parameters = Parameters.ToArray();
                data.SetValue("Parameters", parameters);
            }
        }

        protected override void ExecuteStatement(ExecutionContext context) {
            var cursorInfo = new CursorInfo(CursorName, Flags, QueryExpression);
            if (Parameters != null) {
                foreach (var parameter in Parameters) {
                    cursorInfo.Parameters.Add(parameter);
                }
            }

            context.Request.Query.DeclareCursor(cursorInfo);
        }

        #region Serializer

        //internal class Serializer : ObjectBinarySerializer<DeclareCursorStatement> {
        //  public override void Serialize(DeclareCursorStatement obj, BinaryWriter writer) {
        //      writer.Write(obj.CursorName);
        //      writer.Write((byte)obj.Flags);

        //      if (obj.Parameters != null) {
        //          var pars = obj.Parameters.ToArray();
        //          var parLength = pars.Length;
        //          writer.Write(parLength);

        //          for (int i = 0; i < parLength; i++) {
        //              CursorParameter.Serialize(pars[i], writer);
        //          }
        //      } else {
        //          writer.Write(0);
        //      }

        //      SqlExpression.Serialize(obj.QueryExpression, writer);
        //  }

        //  public override DeclareCursorStatement Deserialize(BinaryReader reader) {
        //      var cursorName = reader.ReadString();
        //      var flags = (CursorFlags) reader.ReadByte();

        //      var pars = new List<CursorParameter>();
        //      var parLength = reader.ReadInt32();
        //      for (int i = 0; i < parLength; i++) {
        //          var param = CursorParameter.Deserialize(reader);
        //          pars.Add(param);
        //      }

        //      var queryExpression = SqlExpression.Deserialize(reader) as SqlQueryExpression;

        //      return new DeclareCursorStatement(cursorName, pars.ToArray(), flags, queryExpression);
        //  }
        //}

        #endregion
    }
}