public string Update(Student aStudent) { string message = ""; aStudent.RoomNo = aStudent.RoomPosition.Remove(aStudent.RoomPosition.Length - 2, 2); try { SqlConnectionObj.Open(); string roomPos; string roomQuery = String.Format("select roomPosition from tbl_Student where studentId='{0}'", aStudent.StudentId); SqlCommandObj.CommandText = roomQuery; object roomp = SqlCommandObj.ExecuteScalar(); roomPos = roomp.ToString(); if (roomPos != aStudent.RoomPosition) { string queryRoom = "insert into tbl_room"; queryRoom = String.Format("insert into tbl_room values ('{0}')", roomPos); SqlCommandObj.CommandText = queryRoom; SqlCommandObj.ExecuteNonQuery(); } SqlConnectionObj.Close(); SqlConnectionObj.Open(); string query = String.Format( "UPDATE tbl_Student SET name='{0}',department='{1}',session='{2}',hall='{3}',email='{4}',roomPosition='{5}',roomNo='{6}',fathername='{7}',address='{8}',school='{9}',college='{10}',district='{11}' WHERE studentId='{12}'", aStudent.Name, aStudent.Department, aStudent.Session, aStudent.HallName, aStudent.Email, aStudent.RoomPosition, aStudent.RoomNo, aStudent.Fathername, aStudent.Address, aStudent.School, aStudent.College, aStudent.District, aStudent.StudentId); SqlCommandObj.CommandText = query; SqlCommandObj.ExecuteNonQuery(); message = "Employee: " + aStudent.Name + " has been Updated"; query = String.Format("delete from tbl_room where roomNo='{0}'", aStudent.RoomPosition); SqlCommandObj.CommandText = query; SqlCommandObj.ExecuteNonQuery(); } catch (Exception exception) { throw new Exception("Error!!!", exception); } finally { if (SqlConnectionObj != null && SqlConnectionObj.State == ConnectionState.Open) { SqlConnectionObj.Close(); } } return(message); }