database design books

Database model (ID-PID): A father has many children, and a child has only one father, such a structure is a tree. In a database table, the ID and PID (parent_id) are designed. A tree is stored by ID and PID. From the object-oriented design point of view, in the tree node class is not suitable for PID, a node has 1 or 0 fathers, and 0 or children. So the

third entity between the two. In this way, the original a many-to-many relationship, now becomes two one-to-many relationship. To properly assign the original two entity's attributes to three entities. The third entity here is essentially a more complex relationship that corresponds to a basic table. Generally speaking, the database design tool does not recognize many-to-many relationships, but it can hand

(20) Cannot be blank User Password User_type Int Cannot be blank User Group ID, associated with user_group.group_id This user group architecture is used. To add a new user, you only need to specify the user group to which the new user belongs. When the system needs to add new features or modify the permissions of old features, only the operation menu and user group table records are used, and the functions of the original user can be changed accordingly. Of course,

Database Design Skills and database skills 1. Relationship between original documents and entities It can be a one-to-one, one-to-many, and many-to-many relationship. In general, they are a one-to-one relationship: an original document corresponds to only one entity. In special circumstances, they may be one-to-many or many-to-one relationships, that is, one ori

MYSQL database design and database design example (I) preparations before bitsCN.com database design and database design

corresponds to a basic table. Generally speaking, database design tools do not recognize many-to-many relationships, but can handle many-to-many relationships. Example 3: In the Library information System, "book" is an entity, "reader" is also an entity. The relationship between the two entities is a typical many-to-many relationship: A book can be borrowed by many readers at different times, and a reader

MySQL database design specifications and mysql design specificationsReprinted by songdeyouxiang 1. Database naming rulesIt consists of 26 English letters (case sensitive) and 0-9 Natural Numbers (not frequently needed) with an underscore;The name must be concise and clear (the name cannot exceed 30 characters );For exa

7, a library lending management database requirements for the following services: (1) The variety, quantity and location of existing books in the stacks can be inquired at any time. All types of books can be uniquely identified by the ISBN. (2) At any time to check the books to borrow, including the borrower's unit, n

Summary: For database design, we generally start from the conceptual model. In the conceptual model design phase, we focus on analyzing the logical structure of data to avoid getting into the specific storage details, all designs are irrelevant to specific database products to be used in the future. This article is sui

1. Test the existing environment When designing a new database, you should not only carefully study the business needs, but also examine the existing system. Most Databases Projects are not built from scratch. Normally, there will always be existing systems within the Organization to meet specific needs (there may be no real Automatically calculated ). Obviously, the existing system is not perfect, otherwise you do not have to create a new system. H

Transfer http://www.wgjz.com/database/other/20070515/89173.html When it comes to databases, I don't think we have to talk about the data structure first. In 1996, when I first went to college to study computer programming, the teacher told us that computer programs = data structures + algorithms. Although the current development of programs has gradually transitioned from process-oriented to object-oriented, I strongly agree with the formula that the

General permission management design (database structure design) and permission management structure designI. Preface The application of the permission management system should be used in three different ways, A. Permission B. Assign permissions. C. Grant Permissions This article only analyzes the application levels of "Use Permission" and "assign permission", an

Design | data | database | Database design Some conceptions of database design (pattern and database design II) ;) Please give us m

Employee Information table. If there is no departmental information table, it should be built according to the third paradigm (3NF), otherwise there will be a lot of data redundancy. The bath-cod paradigm (BCNF) is a subset of the third paradigm (3NF) that satisfies the bath-cod paradigm (BCNF) must satisfy the third paradigm (3NF). Typically, the bath-cod paradigm is considered to have no new design specifications, but is more demanding in

Database technology is the most effective means of information resource management. Database design is the core and foundation of establishing database and its application system, it requires to construct a better database mode for the specified application environment, set

MYSQL database design and database design example (2) bitsCN.com database design-requirement analysis 1> The main task or function of requirement analysis is to investigate in detail the objects to be processed in the real world,