Preface:
Database learning, from the VB textbook, to the Student information management system, the first computer room charge system VB version of the completion of the database, I am no longer unfamiliar, after the self-study test, we are further learning, database this book, before the database is on paper, so to speak, Because I did not set up a database, to the personal computer room fee system reconfiguration, look at the database before, really very redundant, so I have to set up a database, then start it!.
Core:One, document-driven to start the personal reconstruction of the computer room charge system, first of all, start with the document, 11 documents, re-contact is no longer unfamiliar, database design is in each phase of the document gradually completed, today we focus on the database design, then, How does the design of the database be embodied in every stage of the document? Below, please follow the footsteps of small series: is the project development in each phase corresponding to the design of the database.
from the entire life cycle of a database: divided into the following sections
requirements Analysis: At this stage, there are four main items:
1, collect demand information
2, analyze and organize
3. Data flow Diagram
4. Information dictionary
composition: Data stream Data item ; Data Village Storage Processing
Conceptual Design :
Abstract The user requirements from the requirements analysis phase into the conceptual structure of the database,
e-r Map: Local and global
local ER diagram design, From the data flow chart to determine the entity and related properties in the flow chart, according to the flow chart in the process of processing, determine the relationship between entities eg. this is my design database when the drawing, only for your reference!
Logical Structure Design :
Transformation of conceptual structure to relational model
Each entity has a table corresponding to it, the attribute of the entity is converted into a property of the table, the primary key of the entity is converted to the primary key of the table
Optimization
Design User sub-mode
Physical Structure Design
Determine the physical structure of a database
Implementation of the database
Establish database structure, data loading, application development, database trial run
Database operation and Maintenance
second, the design of the database 1. Changesfor the current computer room charge system, I made the following changes to the table: A, the original student form of the Student table and card table two tables B. Combine on-duty teachers and work records into a single table C, the upper and lower two tables are combined into a single table D. Combine daily and weekly bills into one table 2, the establishment of methods A. Traditional methods : Right-click the database, select New database, then go to the next page fill in the database name, then in the first figure, find your new database , find the table , right click on the new table, you can design the database.
B, EAset up the database in the EA, C,PowerDesignerwhen commenting on a blog, see students use this to build a database. The way the database is built may be, and more needs to be explored. 3. Perfecting the database This is the nine-sheet list of the database I built .As an example: Third, attention1. Data type When designing data types, you need to know which data type is appropriate for each data type. 2. Is the empty in designing the data, consider whether the field can be empty and fully considered. 3. Primary foreign key for each table, there will be a primary key and a foreign key, but a table is special, it is independent, is the basic data set that table. 4. Naming rules database naming to standardize, in my design, looked at a lot of information, but for this specification, I am not particularly clear, at the beginning, this preparation to do a good job.
Summary:we need to learn a lot more knowledge! Come on!
"Database design-Contact the real You"
