Designing and implementing a versatile data access tier for an ASP.NET application

using System;
using System.Data;
using System.Data.SqlClient;
namespace DAT
{

	abstract public class  PMFactory
	{
		/// <summary>
		/// This is the super class of PMFactory_In and PMFactory_Out
		/// which are responsible for creating various kind of SqlParameters.
		/// This pattern corresponds  to the pattern �abstract factory� and two majar types
		/// are  ParameterDirection.Input and  ParameterDirection.Output
		/// </summary>
		public PMFactory()
		{
			
		}
       
		/// <summary>
		/// Creates SqlParameter  for DbType: int  with the size:4   
		/// </summary>
		/// <param name="strName">Name of the Parameter</param>
		/// <param name="iValue">SqlParameter</param>
		abstract public SqlParameter GetPMInt4(string strName);

		/// <summary>
		/// Creates SqlParameter DbType:Char with the length 5
		/// </summary>
		/// <param name="strName">Name of the Parameter</param>
		/// <returns>SqlParameter</returns>
		abstract public SqlParameter GetPMChar5(string strName);
		/// <summary>
		/// Creates SqlParameter DbType:VChar with the length 5
		/// </summary>
		/// <param name="strName">Name of the Parameter</param>
		/// <returns>SqlParameter</returns>
		abstract public SqlParameter GetPMVChar5(string strName);

		/// <summary>
		/// Creates SqlParameter Image
		/// </summary>
		/// <param name="strName">Name of the Parameter</param>
		abstract public  SqlParameter GetPMImage(string strName);
	}


	/// <summary>
	/// Responsible for creating  SqlParameters type:Input  
	/// </summary>
	public class PMFactory_In:PMFactory
	{

		/// <summary>
		/// This class is derived  from PMFactory   and 
		/// responsible for the creating input SqlParameters
		/// </summary>
		public PMFactory_In()
		{
			
		}
       
		/// <summary>
		/// Creates input SqlParameter  for DbType: int  and size:4   
		/// </summary>
		/// <param name="strName">Name of the parameter</param>
		/// <param name="iValue">Value of the parameter</param>
		/// <returns>SqlParameter</returns>
		public override SqlParameter GetPMInt4(string strName)
		{
			try
			{
                SqlParameter oParameter = new SqlParameter(strName,SqlDbType.Int,4);
				oParameter.Direction = ParameterDirection.Input;
				return oParameter;

			}
			catch
			{
               throw;
			}
		}

		/// <summary>
		/// Creates SqlParameter for DbType:Image
		/// </summary>
		/// <param name="strName"></param>
		/// <returns></returns>
		public override SqlParameter GetPMImage(string strName)
		{
			try
			{
				SqlParameter oParameter = new SqlParameter(strName,SqlDbType.Image);
				oParameter.Direction = ParameterDirection.Input;
				return oParameter;

			}
			catch
			{
				throw;
			}
		}

		/// <summary>
		/// Creates input SqlParameter  for DbType: Char with the length  5 
		/// </summary>
		/// <param name="strName">Name of the parameter</param>
		/// <param name="iValue">SqlParameter</param>
		/// <returns>SqlParameter</returns>
		public override SqlParameter GetPMChar5(string strName)
		{
			try
			{
				SqlParameter oParameter = new SqlParameter(strName,SqlDbType.Char,5);
				oParameter.Direction = ParameterDirection.Input;
				return oParameter;

			}
			catch
			{
				throw;
			}
		}

		/// <summary>
		/// Creates input SqlParameter  for DbType: VarChar with the length  5 
		/// </summary>
		/// <param name="strName">Name of the parameter</param>
		/// <param name="iValue">SqlParameter</param>
		/// <returns>SqlParameter</returns>
		public override SqlParameter GetPMVChar5(string strName)
		{
			try
			{
				SqlParameter oParameter = new SqlParameter(strName,SqlDbType.VarChar,5);
				oParameter.Direction = ParameterDirection.Input;
				return oParameter;
			}
			catch
			{
				throw;
			}
		}

	}

	/// <summary>
	/// Responsible for creating  SqlParameters type:Input  
	/// </summary>
	public  class PMFactory_Out:PMFactory
	{

		/// <summary>
		/// This class is derived  from PMFactory   and 
		/// responsible for the creating output SqlParameters 
		/// </summary>
		public PMFactory_Out()
		{
			
		}

		/// <summary>
		/// Creates output SqlParameter  for DbType: int with size:4   
		/// </summary>
		/// <param name="strName">Name of the parameter</param>
		/// <returns>SqlParameter</returns>
		public override SqlParameter GetPMInt4(string strName)
		{
			try
			{
				SqlParameter oParameter = new SqlParameter(strName,SqlDbType.Int,4);
				oParameter.Direction = ParameterDirection.Output;
				return oParameter;
			}
			catch
			{
				throw;
			}
		}


		/// <summary>
		/// Creates SqlParameter for DbType:Image
		/// </summary>
		/// <param name="strName"></param>
		/// <returns></returns>
		public override SqlParameter GetPMImage(string strName)
		{
			try
			{
				SqlParameter oParameter = new SqlParameter(strName,SqlDbType.Image);
				oParameter.Direction = ParameterDirection.Output;
				return oParameter;

			}
			catch
			{
				throw;
			}
		}

		/// <summary>
		/// Creates output SqlParameter  for DbType: Char with the length  5 
		/// </summary>
		/// <param name="strName">Name of the parameter</param>
		/// <param name="iValue">SqlParameter</param>
		/// <returns>SqlParameter</returns>
		public override SqlParameter GetPMChar5(string strName)
		{
			try
			{
				SqlParameter oParameter = new SqlParameter(strName,SqlDbType.Char,5);
				oParameter.Direction = ParameterDirection.Output;
				return oParameter;

			}
			catch
			{
				throw;
			}
		}

		/// <summary>
		/// Creates output SqlParameter  for DbType: VChar with the length  5 
		/// </summary>
		/// <param name="strName">Name of the parameter</param>
		/// <param name="iValue">SqlParameter</param>
		/// <returns>SqlParameter</returns>
		public override SqlParameter GetPMVChar5(string strName)
		{
			try
			{
				SqlParameter oParameter = new SqlParameter(strName,SqlDbType.VarChar,5);
				oParameter.Direction = ParameterDirection.Output;
				return oParameter;
			}
			catch
			{
				throw;
			}
		}


	}
}