Data room Charging System Series 6: Key Points Analysis

The data room charging system has been completed for a long time, but it has not been updated. The summary is not very good. Please make up it now .... The data room charging system is the last module of vb and database learning. It is also the first system that has no source code. It is a breakthrough for us both in terms of ideology and logic, it is important to keep a clear mind,

The data room charging system has been completed for a long time, but it has not been updated. The summary is not very good. Please make up it now .... The data room charging system is the last module of vb and database learning. It is also the first system that has no source code. It is a breakthrough for us both in terms of ideology and logic, it is important to keep a clear mind,

The data room charging system has been completed for a long time, but it has not been updated. The summary is not very good. Please make up it now .... The data room charging system is the last module of vb and database learning. It is also the first system that has no source code. It is a breakthrough for us both in terms of ideology and logic, it is very important to keep a clear mind. Next we will introduce the data center charging system. The figure below gives the first impression. It's so big (to see it more clearly, enlarge it ...), The data room charging system is divided into three modules: general users, operators and administrators. The modules correspond to the functions they can implement and tables used in the database.

Differences between common users, operators, and administrators:

Generally, the user's primary permission is to view, view the balance, view the computer record, view the computer status, and view the recharge record.

The operator's main function is to manage card numbers (registration, recharge, card sales, and so on) in addition to functions that can be implemented by general users)

The Administrator has the highest permissions. The administrator can manage operators and general users, check out accounts, and summarize daily consumption.

Anatomy of each form:

1. login window

Key points: the interface is clear and simple, and the user name and password are restricted to prevent SQL Injection problems. Enter the user name and password correctly.

2, on and off the machine: Here is not detailed introduction, view http://blog.csdn.net/chenxiaochan/article/details/38645007

3. Force the user to go offline:

The process for force disconnection is the same as that for normal disconnection. Select this record and click force drop to select a user.

4. view the student balance:

Key Point Analysis: Generally, users can view the information and do not have the right to modify the student information. Therefore, the value of the locked attribute must be changed to TRUE only when the number is entered in the text box.

5. Recharge

Key Point Analysis: the length of the student ID is limited. The card number and student ID cannot be the same as the existing ones. The amount and recharge amount are consistent, which involves the use of the two tables.

6. Combined Query

Key Point Analysis: note that an empty record is added to each condition to be searched. If the first record is not selected, the query condition cannot be selected in the second or third record, if the second record is not selected, the query condition cannot be selected in the third record.

7. add and delete users

Key Point Analysis: Click the user-level drop-down box to display the user name, name, and account owner for the database permission in the MSHFlexGrid control.

When you click the Add button, the default user level is the selected permission name of the previous form and cannot be modified.

8. Basic data settings

Key Point Analysis: This form is mainly related to the calculation of the consumption amount. Pay attention to the setting of the preparation time and at least the machine time and the minimum amount.

9. Checkout

Key Point Analysis: Logical Analysis of checkout

Card number in use

The number of cards that are in the "not used" status

Total number of cards sold: number of cards sold-number of cards withdrawn

The recharge amount is the sum of the recharge count in the recharge_info table.

The refund amount is the sum of the refund amount in the cancelcard_info table.

Total amount receivable: Recharge Amount-refund amount

10. Reports

See http://blog.csdn.net/chenxiaochan/article/details/38709619 for details

Summary: at the beginning of the data room charging system, I hardly considered the demand analysis. Later, I learned these problems in the soft engineering video and self-examination books, and began to pay attention to these problems, every form in the system has its own reason, which may not be used at this stage. The next article describes how the data center charging system is completed.