/// <summary>
        /// 返回一个可供操作DataTable，支持Sql和OleDB
        /// </summary>
        /// <param name="strSQL">SQL语句</param>
        /// <param name="Connection">一个连接对象(OleDb或Sql类型)</param>
        /// <returns></returns>
        public static DataTable GetDataTable(string strSQL,IDbConnection Connection)
        {
            
            DataTable dt     = new DataTable("BT");
            DbDataAdapter da = null;                            
            if(Connection is SqlConnection)
            {
                da = new SqlDataAdapter(strSQL, Connection as SqlConnection);
            }
            else
            if(Connection is OleDbConnection)
            {
                da = new OleDbDataAdapter(strSQL, Connection as OleDbConnection);
            }
            else
            {
                throw new Exception("请传递一个OleDb或Sql类型的连接对象!");
            }
            da.Fill(dt);
            return dt;
        }

------解决方案--------------------

 /// <summary>
       /// 执行SQL语句，返回影响的记录数
       /// </summary>
       /// <param name="SQLString">SQL语句</param>
       /// <returns>影响的记录数</returns>
       public static int ExecuteSql(string SQLString)
       {
           using (SqlConnection connection = new SqlConnection(connectionString))
           {
               using (SqlCommand cmd = new SqlCommand(SQLString, connection))
               {
                   try
                   {
                       connection.Open();
                       int rows = cmd.ExecuteNonQuery();
                       return rows;
                   }
                   catch (System.Data.SqlClient.SqlException e)
                   {
                       connection.Close();
                       throw e;
                   }
               }
           }
       }
C# code

/// <summary>
        /// 执行查询语句，返回DataSet
        /// </summary>
        /// <param name="SQLString">查询语句</param>
        /// <returns>DataSet</returns>
        public static DataSet Query(string SQLString)
        {
            using (SqlConnection connection = new SqlConnection(connectionString))
            {
                DataSet ds = new DataSet();
                try
                {
                    connection.Open();
                    SqlDataAdapter command = new SqlDataAdapter(SQLString, connection);
                    command.Fill(ds, "ds");
                }
                catch (System.Data.SqlClient.SqlException ex)
                {
                    throw new Exception(ex.Message);
                }
                return ds;
            }
        }