Exception Handling in 3-Tier Architecture

using System;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.Common;
using System.Configuration;
using System.Collections.Generic;
using Microsoft.Practices.EnterpriseLibrary.Common;
using Microsoft.Practices.EnterpriseLibrary.Data;
using Common.Helpers.ExceptionHandling;

namespace Common.Helpers.DataAccess
{
   public static class SqlHelper
   {
      private static string AppDatabaseName;

      static SqlHelper()
      {
         AppDatabaseName = ConfigurationManager.AppSettings["AppDatabaseName"];
      }

      private static Database GetDatabase(string dbName)
      {
         try
         {
            Database db = null;
            if (dbName == null)
            {
               return db = DatabaseFactory.CreateDatabase();
            }
            else
            {
               return db = DatabaseFactory.CreateDatabase(dbName);
            }
            return db;
         }
         catch (Exception ex)
         {
            throw ex;
         }
      }

      public static DataTable GetDataTable(string spName)
      {
         try
         {
            Database db = GetDatabase(AppDatabaseName);
            DbCommand cmd = db.GetStoredProcCommand(spName);
            DataSet ds = db.ExecuteDataSet(cmd);
            DataTable dt = ds.Tables[0];
            return dt;
         }
         catch (Exception ex)
         {
            bool rethrow = DataAccessExceptionHandler.HandleException(ref ex);
            if (rethrow)
            {
               throw ex;
            }
            return null;
         }
      }

      public static DataTable GetDataTable(string spName, object[] parameters)
      {
         try
         {
            Database db = GetDatabase(AppDatabaseName);
            DbCommand cmd = db.GetStoredProcCommand(spName, parameters);
            DataSet ds = db.ExecuteDataSet(cmd);
            DataTable dt = ds.Tables[0];
            return dt;
         }
         catch (Exception ex)
         {
            bool rethrow = DataAccessExceptionHandler.HandleException(ref ex);
            if (rethrow)
            {
               throw ex;
            }
            return null;
         }
      }

      public static IDataReader GetDataReader(string spName)
      {
         try
         {
            Database db = GetDatabase(AppDatabaseName);
            IDataReader reader = db.ExecuteReader(spName);
            return reader;
         }
         catch (Exception ex)
         {
            bool rethrow = DataAccessExceptionHandler.HandleException(ref ex);
            if (rethrow)
            {
               throw ex;
            }
            return null;
         }
      }

      public static IDataReader GetDataReader(string spName, object[] parameters)
      {
         try
         {
            Database db = GetDatabase(AppDatabaseName);
            IDataReader reader = db.ExecuteReader(spName, parameters);
            return reader;
         }
         catch (Exception ex)
         {
            bool rethrow = DataAccessExceptionHandler.HandleException(ref ex);
            if (rethrow)
            {
               throw ex;
            }
            return null;
         }
      }

      public static object ExecuteNonQuery(string spName, object[] inParameters, bool outParameters)
      {
         try
         {
            Database db = GetDatabase(AppDatabaseName);
            DbCommand cmd = db.GetStoredProcCommand(spName, inParameters);
            db.ExecuteNonQuery(cmd);
            if (outParameters)
            {
               return (object)(cmd.Parameters["Outparam"].Value);
            }
            return null;
         }
         catch (Exception ex)
         {
            bool rethrow = DataAccessExceptionHandler.HandleException(ref ex);
            if (rethrow)
            {
               throw ex;
            }
            return null;
         }
      }
   }
}