Developing test database and online examination system with ASP (5)

4. 3. 2. Query module

All users in the system can retrieve the information such as questions, test papers, users and messages. But it is more complicated, but it has realized a combination of many conditions, which is very suitable for a large number of questions library. The latter three are relatively simple, and in the case of "default" or "blank", all their information is displayed in the default field of the system in the table. It is more flexible and convenient to use.

4. 3. 3, modify the module

In addition to only modify their own part of the information (including user accounts, passwords and e-mail), but also modify the questions and test papers, and leave messages are not allowed to modify. Changes can be made as long as the user selects the account and the input number. However, the primary keys in each table are not allowed to be modified, avoiding the confusion of data in the system or overwriting other useful data. If the user performs an illegal operation, it must be rerun.

4. 3. 4. Group Volume module

In the process of the group, we will certainly encounter a lot of questions about the same teaching content, which is called about the same test points. Therefore, when assembling a test paper, for the same test point of the questions can only be a problem. Here, a quick selection algorithm is designed, the algorithm can determine whether the examination points have been selected by a comparison, and can focus on selecting a test point. That is, each problem has a correlation code, for the same chapter, the same section, the same test point of the problem, the relevant code is the same, obviously, the relevant code in the previous chapters are less than the relevant code in the following chapters. Therefore, in the group volume, the same test paper is not allowed to appear the same relevant code of the test. So, in the process of choosing a topic, it is necessary to compare the relevant codes of the questions that have been selected, if the relevant code of the question and the relevant code of the selected questions are different, then the problem can be added to the test paper, otherwise, give up the problem, the topic again.

Below, only consider the best case, that is, each of the selected questions are just not selected, each of the selected questions to be compared with the selected questions, assuming that the M problem has been selected, and then select the next question, you need to compare m times, you may want to set a test paper for the total number of n, in the best case, the total number of comparisons are:

0,1, 2,... N-2,n-1

That is, the time complexity of O (N), so as to ensure that the following algorithm to select the question number is valid.