VB. Net data center charging system-Database Design

Database Design refers to the process of designing the database structure according to user requirements. Specifically, database design refers to constructing the optimal database mode under the guidance of the theory of relational database for a given application environment, create a database and its Application System on the database management system to effectively store data and meet various user needs. For example

Database Design refers to the process of designing the database structure according to user requirements. Specifically, database design refers to constructing the optimal database mode under the guidance of the theory of relational database for a given application environment, create a database and its Application System on the database management system to effectively store data and meet various user needs. For example

Database Design refers to the process of designing the database structure according to user requirements. Specifically, database design refers to constructing the optimal database mode under the guidance of the theory of relational database for a given application environment, create a database and its Application System on the database management system to effectively store data and meet various user needs. In the past and times, everyone has their own ideas about how to design a database. Therefore, there is no difference between database design and good or bad. Proper database design is the best.

Go through the test-database system principle, read the video from instructor Yan jianling, and have a little understanding of the database design. The VB version of the data center charging system directly uses the database generated by the original script, at that time, I did not have a particularly in-depth research on the Content of database design. I had to pay back the debt in the morning and evening. I think it's time. In the past few days, VB. net version of the data center charging system officially started, only to find that the database design is a learning, next, combined with the data center charging system, summarize the database design.

First, the database design involves the following six steps:

1. Requirement Analysis: Understand the user's data requirements, processing requirements, security and integrity requirements;
2. Conceptual Design: design the conceptual model of the system through data abstraction, which is generally a E-R model;
3. Logical Structure Design: design the system mode and external mode. The relational model mainly includes basic tables and views;
4. Physical Structure Design: design the data storage structure and access methods, such as index design;
5. System implementation: organize data warehouse receiving, compiling applications, and test run;
6. Operation and maintenance: the system is put into operation and long-term maintenance work.

This article will discuss demand analysis, conceptual design, and logical structure design. Here we will briefly discuss the requirements of the data center charging system, which has three Role users: general users, operator, administrator. Different permissions have different permissions:

A. What common functions can be implemented by users?
A. view the balance in the student card, query the student's basic information through the card number, and display the balance.
B. view the host records, query the host records, names, date and time of the host, consumption amount, and export the Execl table.
C. view the recharge record, use the card number to query the Recharge Amount, recharge date, recharge time, recharge instructor, and export the Excel form.
D. query the status of a student on the machine and force the student to perform the off-the-machine operation.
E. Change the password.

B. The operator refers to the person who handles certain business and has a higher level than the average user. In addition to the functions of the on-duty personnel, the operator can also execute additional functions:

A. register the card number and register a new card.
B,Recharge: the recharge amount is used to display the recharge card number, the balance in the last card, the balance in the current card, the recharge date and time, and the teacher.
C. Return the card, cancel the card, and refund the balance in the student card.
D. query the charge (refund) amount, enter the start date and end date, query the Recharge Amount, recharge date and time, recharge the instructor, and export the Execl table.
E. Maintain the basic information of students and operate employee records, and use combined queries.
F. query the statistical information of students on the computer. Use Combined Query to export the Execl table.

C. The administrator can manage all the information of the system at the highest level. In addition to the functions of the shift attendants and operators, the administrator can also handle other operations:
A. Check out
B. add or delete users, and add or delete accounts of different levels
C. Set the basic data, including the computer fee and other information
D. view the teachers on duty
E. daily and weekly close, involving reports.

According to the above requirement analysis, design the ER Model (not very complete. If you have any opinions, please leave a message). For example:

Release/K1vLS0vajK/b7dv + KjrLb + release/b7dv + K6zbHtzqrA/aOsyrXP1rT6wuvI58/codecomvcd4kpha + release = "brush: SQL; "> create database mycharge -- create mycharge database gouser mycharge -- go to mycharge database gocreate table studen -- create table STUDENT (Sno char (10) primary key in student database, sname char (10), Ssex, Sage int, Sdept char (10 ))The following table lists the data room charging systems:

1. Student table: card number, student ID, name, type, gender, department, grade, class, amount, status, and remarks.
2. On-board table: card number, type, student number, name, department, gender, on-board date, off-board date, on-board time, off-board time, consumption time, consumption amount, and balance.
3. Recharge table: card number, Recharge Amount, recharge time, and recharge instructor.
4. User table: User Name, password, identity, and operator.
5. Return form: card number, refund amount, return time, refund instructor, and check status.
6. Operate the employee work record table: serial number, instructor, identity, registration date, registration time, cancellation date, and cancellation time.
7. Checkout information table: number of cards sold, total number of cards sold, number of cards refunded, total amount receivable, recharge amount, and temporary charge amount.
8. Basic data settings information table: fixed cost for half an hour, temporary cost for half an hour, incremental unit time, at least machine time, preparation time, and minimum amount.
9. On-duty instructor information table: Record Number, instructor name, identity, logon date, and logon time.
10. Daily checkout information table: last recharge card balance, daily Recharge Amount, daily consumption amount, current recharge card amount, and date.
11. Weekly checkout information table: last recharge card amount, current Recharge Amount, current consumption amount, current recharge card balance, and date.

There are many defects in Database Design for the first time. If you have different opinions, you are welcome to leave a message. The fee system of the IDC is a self-built version, which is not yet complete ......