using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.Common;
using System.Runtime.Serialization;
using CategoryTheory;
using DiagramUI;
namespace DataSetService
{
/// <summary>
/// Wrapper of statement
/// </summary>
[SerializableAttribute()]
public class StatementWrapper : AbstractDataProvider, IRemovableObject
{
#region Fields
/// <summary>
/// Name of factory
/// </summary>
protected string factoryName;
/// <summary>
/// Database command
/// </summary>
protected DbCommand command;
/// <summary>
/// Database connection
/// </summary>
protected DbConnection connection;
/// <summary>
/// Data adapter
/// </summary>
private IDbDataAdapter adapter;
/// <summary>
/// Data set
/// </summary>
private DataSet dataSet;
#endregion
#region Constructors
/// <summary>
/// Default constuctor
/// </summary>
public StatementWrapper()
{
}
/// <summary>
/// Deserialization constructor
/// </summary>
/// <param name="info">Serialization info</param>
/// <param name="context">Streaming context</param>
protected StatementWrapper(SerializationInfo info, StreamingContext context)
: base(info, context)
{
factoryName = info.GetValue("FactoryName", typeof(string)) + "";
Init(info, context);
}
#endregion
#region ISerializable Members
/// <summary>
/// ISerializable interface implementation
/// </summary>
/// <param name="info">Serialization info</param>
/// <param name="context">Streaming context</param>
public override void GetObjectData(SerializationInfo info, StreamingContext context)
{
base.GetObjectData(info, context);
info.AddValue("FactoryName", factoryName);
}
#endregion
#region Members
/// <summary>
/// Schema of dataset
/// </summary>
public DataSet Schema
{
get
{
IDataSetFactory factory = DataSetFactoryChooser.Chooser[factoryName];
DbConnection connection = factory.Connection;
connection.ConnectionString = connectionString;
return factory.GetData(connection);
}
}
/// <summary>
/// Provided data set
/// </summary>
public override DataSet DataSet
{
get
{
try
{
if (dataSet == null)
{
StreamingContext ctx = new StreamingContext();
Init(null, ctx);
connection.Open();
dataSet = new DataSet();
adapter.Fill(dataSet);
connection.Close();
}
return dataSet;
}
catch (Exception ex)
{
ex.Log();
}
return null;
}
}
/// <summary>
/// Updates itself
/// </summary>
public void Update()
{
dataSet = null;
}
/// <summary>
/// Name of factory
/// </summary>
public string FactoryName
{
get
{
return factoryName;
}
set
{
factoryName = value;
if (value != null)
{
factory = DataSetFactoryChooser.Chooser[factoryName];
}
}
}
/// <summary>
/// Initialization
/// </summary>
/// <param name="info">Serialization info</param>
/// <param name="context">Streaming context</param>
protected virtual void Init(SerializationInfo info, StreamingContext context)
{
factory = DataSetFactoryChooser.Chooser[factoryName];
connection = factory.Connection;
connection.ConnectionString = connectionString;
command = factory.Command;
command.Connection = connection;
command.CommandType = CommandType.Text;
command.CommandText = FinalStatement;
adapter = factory.Adapter;
adapter.SelectCommand = command;
}
#endregion
#region IRemovableObject Members
void IRemovableObject.RemoveObject()
{
if (dataSet != null)
{
dataSet.Dispose();
}
}
#endregion
}
}
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