A Handy Code to Get Your Project Connected to Any Database by ADO.NET

using System;
using System.Data;
using System.Data.Common;
using System.Data.Sql;
using System.Data.SqlTypes;
using System.Data.SqlClient;
using System.Configuration;
using System.Web;
using System.Web.Configuration;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

/// <summary>
/// Top Layer For Accessing Data
/// </summary>
public sealed class DataAccess
{
    #region Data Members And Objects Declaration
    readonly string connectionString;
    readonly string provider;
    FactoryGoverner governer;
    SQLFactory sqlFactory = new SQLFactory();
    ProviderAgnosticFactory pAFactory = new ProviderAgnosticFactory();
    SqlDataReader dR;
    DbDataReader dbDR;
    #endregion

    #region Constructor For DataAccess
    public DataAccess(string configSectionName)
    {
        connectionString = WebConfigurationManager.ConnectionStrings[configSectionName].ToString();
        provider = WebConfigurationManager.ConnectionStrings[configSectionName].ProviderName;
    }

    public DataAccess(string conStr, string providerName)
    {
        connectionString = conStr;
        provider = providerName;
    }
    #endregion

    #region Private Methods
    private void PrepareEnvironment(QueryType queryType)
    {
        try
        {
            switch (provider)
            {
                case "System.Data.SqlClient":
                    governer = sqlFactory;
                    governer.InvokeFactory(FactoryCodes.SQLClient, connectionString, queryType);
                    break;
                case "System.Data.OracleClient":
                    governer = pAFactory;
                    governer.InvokeFactory(FactoryCodes.OracleClient, connectionString, queryType);
                    break;
                case "System.Data.OleDb":
                    governer = pAFactory;
                    governer.InvokeFactory(FactoryCodes.OleDB, connectionString, queryType);
                    break;
                case "System.Data.Odbc":
                    governer = pAFactory;
                    governer.InvokeFactory(FactoryCodes.ODBC, connectionString, queryType);
                    break;
                default:
                    throw new UnsupportedFactoryException("Database Is Unsupported");
            }
        }
        catch (NullReferenceException ex)
        {
        }
        catch (UnsupportedFactoryException ex)
        {
        }
    }
    #endregion
    #region Data Access Public Methods
    public DataSet GetDataSet(QueryType queryType, string query, params AgnosticParameter[] argumentsIn)
    {
        PrepareEnvironment(queryType);
        return governer.GetDataSet(query, argumentsIn);
    }

    public SqlDataReader GetSQLReader(QueryType queryType, string query, params AgnosticParameter[] argumentsIn)
    {
        PrepareEnvironment(queryType);
        try
        {
            if (provider != "System.Data.SqlClient")
                throw new UnsupportedFactoryException("Method Not For Non SQL Client");
            else
                return (SqlDataReader)governer.GetReader(query, argumentsIn);
        }
        catch (InvalidCastException ex)
        {

        }
        return dR;
    }

    public DbDataReader GetReader(QueryType queryType, string query, params AgnosticParameter[] argumentsIn)
    {
        PrepareEnvironment(queryType);
        try
        {
            if (provider == "System.Data.SqlClient")
                throw new UnsupportedFactoryException("Method Not For SQL Client");
            else
                return (DbDataReader)governer.GetReader(query, argumentsIn);
        }
        catch (InvalidCastException ex)
        {
        }
        return dbDR;
    }

    public object GetScalarResult(QueryType queryType, string query, params AgnosticParameter[] argumentsIn)
    {
        PrepareEnvironment(queryType);
        return governer.GetScalarResult(query, argumentsIn);
    }

    public int GetNonQueryResult(QueryType queryType, string query, params AgnosticParameter[] argumentsIn)
    {
        PrepareEnvironment(queryType);
        return governer.GetNonQueryResult(query, argumentsIn);
    }

    public DataSet GetOutParameters(QueryType queryType, string sp_Name, ref AgnosticParameter[] argumentsOut, params AgnosticParameter[] argumentsIn)
    {
        PrepareEnvironment(queryType);
        return governer.GetOutParameters(sp_Name, ref argumentsOut, argumentsIn);
    }
    #endregion
}