在线考试系统优化方案

namespace OnLineExamBLL { public class RoleManager { public static bool InsertRoles(Role role) { if (RoleService.InsertRole(role)) { return true; } else { return false; } } public static List SelectRoles() { RoleService roleservice = new RoleService(); List list = roleservice.SelectRole(); return list; } public static string GetRoleName(String UserID) { using (SqlConnection conn = DBHelp.GetConnection()) { string sql = @"select RoleName from dbo.Role where RoleId =(select RoleId from dbo.Users where UserID='{0}')"; SqlCommand cmd = conn.CreateCommand(); sql = string.Format(sql, UserID); cmd.CommandText = sql; conn.Open(); SqlDataReader dr = cmd.ExecuteReader(); if (dr.Read()) { return dr["RoleName"].ToString(); } dr.Close(); conn.Close(); return ""; } }